Merciful 1/Merciful - Disc 1.iso/software/v/vista_lite/vista_lite_v3.00.txt

Text File | 1995-10-14 | 127KB | 2,727 lines

                  VISTA LITE V3.00 - USER MANUAL
                  ==============================


PROGRAM LICENSE AGREEMENT
-------------------------

The  program  Vistalite  is  copyrighted  by  Hypercube Engineering, and the
related  user  manual  is  copyrighted by Virtual Reality Laboratories, Inc.
You  may  not copy, modify, distribute, transfer or transmit this program or
the  related  manual  except  as is expressly provided in this agreement.You
have  the  non-exclusive  right  to use this program on all of the Commodore
Amiga  computers  within  a  single  household.  You may make as many backup
copies  of  this program as you like, as long as you guarantee that they are
not in use in more than one house hold at a time.  Businesses should contact
VRLI  for  site  licensing.   This program is sold as entertainment, without
warranty  as  to  its suitability to be used for any other purpose.  Virtual
Reality  Laboratories,  Inc.    warrants  to  the original licensee that the
diskette(s)  on  which  Vistalite  is recorded shall be free from defects in
material  and  workmanship  for a period of sixty (60) days from the date of
purchase.    If  such  a  covered defect occurs during the first sixty days,
return  the  disk  to  VRLI,  2341  Ganador Court, San Luis Obispo, CA934O1,
within  five (5) days after the sixty day limit, and we will replace it free
of  charge.   Replacement after the sixty day limit will be done at the rate
of  $10.00 per disk to cover costs of media, shipping and handling.  Virtual
Reality  Laboratories,  Inc.'s  liability  is  limited to the replacement of
defective  media.    This license agreement shall be governed by the laws of
the  United States of America and the State of California.  Commodore Amiga,
Inc.    makes  no  warranties  either  expressed  or  implied, regarding the
enclosed  computer software package, its merchantability, or its fitness for
any  particular  purpose.    Amiga, Amigados, Workbench, Kickstart, and Intu
ition  are  trademarks of Commodore Amiga, Inc.  Turbo Silver is a trademark
of Impulse, Inc.

CONTENTS
--------

INTRODUCTION TO VISTALITE

  GettingStarted
    Vistalite Installation
    A Quick Tour
  What is Vistalite?
  How Vistalite Works
  Some Uses for Vistalite
  Notes on Vistalite
    Vistalite on Accelerated Amigas
    Vistalite Landscapes
    Vistalite Stack Requirements
    Loading Vistalite from the CLI or a Shell
    Limits of Vistalite's World
  Speeding Up Vistalite
  Making the Most of Vistalite
    Lighting
    Snow and Tree Line Setting Considerations
    Changing colors
    Foreground "fatpolys" or "jaggies"
    A note about aesthetics
    Exploration with Vistalite
    Your own data

VISTALITE TUTORIALS

 Tutorial 1: The Basics
   Running Vistalite
   A Quick Introduction
   Loading a DEM Landscape
   Setting Camera and Target
   Viewing Your Camera Position
   Adjusting the Camera Lens
   Making a Smoother Image
    Blend
    Dither
    Gouraud Shading
   Experiment
 Tutorial 2: Making Better Images
   Loading an IFF Image
   Image Quality
   Adding Texture
   Setting the Timber Line
   Drawing Trees
   Setting Tree Density
   Setting the Snow Level
   Adding a Lake
   Adding a River
   Changing the Haze Level
   Setting the Light Direction
   Shadows
   Changing Colors
   Saving a Rendered Image

VISTALITE MENUS

 Project Menu
   Print
   About Vistalite
   About Landscape
   About Image
   Quit
 Load Menu
   Load Vistalite DEM
   Load IFF
 Save Menu
   Save Vistalite DEM
   Save IFF
 GrModes Menu
   320x200
   640x200
   320x400
   640x400
   16 color
   32 color
   EHB
   HAM
   HAM8
   256 color
   Show Render
 Script Menu
   Generate
   Create
   Open
   Add
   Preview
   Execute
   Anim Mode
     VANIM
 CMap Menu
 IQuality Menu
   Low
   Medium
   High
   Ultra

 CONTROL PANEL

   Target
   Camera
   Locking Functions
   P
   dR
   dX
   dY
   dZ
   Bank
   Head
   Pitch
   CMap
   LockP
   SeaLvl
   TreeLn
   SnowLn
   HazeDn
   Lake
   River
   Clouds
   Stars
   Pine, Oak, Palm and Cactus
   TreDn
   TreeSz
   Fcl Ln
   Wide
   Zoom
   Poly
   Dither
   Textur
       O L M H
   PixDth
   Random
   Fractal Landscape Number
   Island
   FrDim
   Frctlz
   Fractal Divisor
   NSEW
   Custom
   Azimth
   Declin
   Rough
   Shadow
   Blend
   GShade
   Render
   Redraw
   View
   Abort

 Color Control Panel

   Colors
   OK
   Spread
   Quit
   Copy
   Swap
   Sound
   Colors
   Sky
   Cliff 1-4
   Snow  1-4
   Bare  1-4
   Tree  1-4
   Beach
   Horizon
   Water 1-5
   SkyHaze
   Haze
   Grass 1-4
   Bark  1-4
   Exposure
   Contrast

THE VISTALITE STATUS WINDOW

   X,Y,Z:
   Generate:
   Color
   Cliffs
   Shade
   Tree
   Sky
   Horizon
   Render:

 VIEWER

 APPENDIX A

 What are Fractals and Fractal Geometry?

 APPENDIX B

   The Landscapes
   ElCapdem:
   HalfDomedem:
   CraterLakedem:
   MSHBdem: and MSHAdem:
   Juliadem: and Mandelbrotdem:
   Vantagedem:
   Arrowhead dem:
   SanGorgoniodem:
   BigSurdem:
   MtBaldydem:
   MtAdamsdem:

 APPENDIX C

 Glossary of Terms
   AI
   Aliasing Artifacts
   Caldera
   Deluxe Paint
   DEM
   Digi Paint
   Digital Elevation Model
   Dithering
   Fat Polys
   Fractal
   Fractal Pro
   HAM
   Haze
   IFF
   Jaggies
   Olympus Mons
   Polygons
   Ray Tracing
   Topography
   Topology
   USGS
 INDEX

INTRODUCTION TO VISTALITE
-------------------------

Getting Started
---------------

Vistalite Installation

Before  installing Vistalite, you should be aware that it requires a minimum
of two megabytes of memory in which to run.

Vistalite requires about 1.5 megabytes of free memory in which to run.  Free
memory  is that memory which is not occupied by AmigaDOS on start up.   Some
of  the  buffers  that  Vistalite  uses  require  large contiguous pieces of
memory.    As  you  use  your  system between reboots, its memory can become
fragmented.    You  may  still have 1.5 megabytes free but not have a single
contiguous  block  large  enough  for some buffers.  If this happens, reboot
your computer.  This has the effect of combining all of the free memory into
a  single  large  block.    In  some of the AGA modes on a hi-res interlaced
screen  (640x512),  Vistalite  requires  a full two megabytes of memory.  In
order  to  make  this  work, if Vistalite is unable to find enough memory to
open  the  image  buffer,  it tries to open a disk file of the same size and
swaps  portions  of  that buffer to a much smaller image buffer.  This saves
about  512 kilobytes of needed memory with a 640x400 screen size in HAM 8 or
256 color mode.

Vistalite  (including  its associated DEM files, sample scripts, etc.) takes
approximately 1.5 megabytes of hard disk space.

Insert  the  Vistalite  Program  Disk into any available disk drive.  Double
click  on  the disk icon to open it.  Double click on the Install icon found
on the Vistalite Program Disk.  The Installer will ask you several questions
about  your  system  and  whether  or  not  you  want Vistalite installed on
floppies.  After installation is complete, you are ready to run Vistalite.

A Quick Tour
------------

Vistalite  is a scaled down version of Vistapro 3.0 which has been specially
engineered  to  be  able  to  run with limited memory.  It makes pictures of
landscapes  from  two  different types of data.  Pictures of real landscapes
are  made  from U.S.  Geological Survey (USGS) Digital Elevation Model (DEM)
data.    You can also explore billions of imaginary fractal landscapes gener
ated from data produced by Vistalite itself.

Starting  with  Vistalite's  main  screen,  you  see  a  rectangular picture
bordered  by  gray  on  the  left two thirds of the screen.  This contains a
Topographic  Map  of  a landscape that you can explore.  The Topographic Map
uses  shades  of  green  to represent the lowest altitudes on the landscape,
browns  to  represent  the middle altitudes, and gray-whites for the highest
altitudes.    You control Vistalite with the buttons in the Control Panel on
the right side of the screen.

Continuing  with our tour of Vistalite, move the red crosshair to the Camera
button and click the left mouse botton.  Note that the Camera button appears
to  be  indented,  which  means  that the crosshair can be used to place the
camera  (the small box on the map) when you click the left mouse button over
the  topographic  map.    Note  that the X, Y and Z coordinate values in the
boxes next to the X, Y and Z buttons change each time you click to set a new
camera location.  The Z coordinate shows the altitude of your camera.  It is
automatically  set  to 30 meters above the point on which you clicked.  When
you  have  placed the camera where you want it, add several hundred units to
the  Z  altitude  by  clicking  on the numerical value and typing in the new
number.   The extra altitude puts the camera far enough above the surface to
reduce the size of polygons in the foreground.

Next, click on the Target button, then click on the topographic map to place
the  target, or the point at which the camera is looking.  A small + appears
on  the  map  to  identify  the  target  location.      This manual contains
information  on how to use all the other controls but, for now, click on the
CMap  button.    This causes Vistalite's Color Control Panel to appear.  The
Color  Control  Panel  is used to adjust the colors, contrast and brightness
used to paint the landscape.  Since this is only a tour, don't change any of
the  settings.    Click  on  the  OK button at the bottom left corner of the
screen  to  return  to  the  primary  control screen.  Using the right mouse
button,  go  to  the  top  left  part  of the primary control screen to view
Vistalite's  pull  down  menus.    Don't  select  any  right  now.  They are
described  in detail in the chapter on Vistalite Menus.  Click on the Render
button  on  the  bottom control panel and wait.  Vistalite will render (draw
and  color)  a  rough  (big polygon) view of the target that you have chosen
from the camera position that you chose.

After it has rendered the picture, a click on any part of the screen returns
you  to the Topographic Map and Control Panel.  Notice that the default Poly
value  is  8.   This is the roughest and fastest view.  It helps you quickly
reset  the  camera view and lighting until you think you have it the way you
want it.  The lower Poly values increase the rendering time, as they yield a
more detailed picture.  Now that you know your way around Vistalite, you may
wish  to  take  a  few  minutes  to  follow  the tutorials.  We designed the
tutorials to teach by doing.  When you have finished the tutorials, you will
have  an  intuitive  understanding  of  Vistalite  which  will increase your
ability  to  use  the  program.  The remainder of this manual is a reference
text  for  your  use should you need detailed information about a particular
feature.

What is Vistalite?
------------------

Vistalite  is a three-dimensionai landscape simulation program.  Using U.S.
Geological  Survey (USGS) Digital elevation Model (DEM) files, Vistalite can
accurately  recreate  real  world  landscapes in vivid detail.  As a fractal
landscape  generator.    Vistalite  can create landscapes from a random seed
number.  Often these landscapes are more interesting than those found in the
real  world.    Vistalite  supports over four billion different fractal land
scapes.  Simply by changing a number, you can create whole new worlds.

Vistalite is also a tool.  Besides simulating real and imaginary landscapes,
it  allows  extraction  of a certain amount of data from the DEM files.  You
can  use  the  program  output as an educational tool, as well as a research
tool  for  the  study  of  topography.    In addition, by simply clicking on
several  buttons,  you can create rivers and lakes in a landscape where none
existed previously.

How Vistalite Works
-------------------

Vistalite  uses a combination of artificial intelligence, chaotic math and a
user  definable set of values to simulate landscapes in their natural state.
At  present,  the  USGS has converted about 40% of the United States and its
territories  to  DEM  files  which  can  potentially be used with Vistalite.
Vistalite  is  a  sing1e frame generator, meaning that it acts like a camera
every  time  you  point  the  camera and click, it renders a new view of the
landscape.   You can view landscapes from a practically infinite combination
of  heights,  angles  and  distances.    Using   the   combination   of user
controllable  values  and  Vistalite's  built  in  routines,  you  can  make
landscapes  as  realistic  or as surreal as you desire.  It is easy to alter
tree  and  snow  lines,  haze,  exposure, rivers, lakes and light sources to
customize the appearance of the landscape.

Vistalite  uses  data  derived  from  United  States Geologic Survey Digital
Elevation  Mapping  files  to generating images.  These files contain coordi
nate  and elevation data at 30 meter (roughly 100ft.) increments.  Each Tiny
Vistalite  DEM  file  contains  about 16,000 elevation data points and gener
ates 32,000 polygons.  Vistalite doesn't know anything about what covers the
terrain.  It doesn't know where the trees or roads are.  It does its best to
color  each polygon (based upon a few numbers that you input) in a realistic
way.    However, it can't draw each rock and tree.  Adding texture and trees
can  result in images containing as many as a hundred times as many polygons
as the landscape by itself.

Some Uses for Vistalite
-----------------------

Vistalite  is  not  only  of interest to scientists and engineers.  Artists,
writers,  teachers,  game  designers,  travelers and anyone just looking for
hours  of  entertainment  will  appreciate  Vistalite.    Artists can design
reallstic  scenery  as  backgrounds  for  their artwork.  Writers can create
worlds  and see them through their characters' eyes.  Geography, geology and
meteorology  teachers can use Vistalite to breathe life into their subjects.
Game designers can make realistic or surrealistic scenery for backgrounds in
their  games.  Travelers, hikers and backpackers can preview their journeys.

Vistalite  can be pure entertainment.  Explore fascinating terrains that you
might  never  have a chance to see or visit distant planets that man has not
yet trod.  Build new worlds that exist nowhere except in the imagination and
then  visit them as if they were really there.  On the other hand, there are
many scientific and business applications for Vistalite.  Environmentalists,
surveyors,  geologists,  architects  and engineers will all find Vistalite a
useful adjunct to their work.

Notes on Vistalite
------------------

Vistalite on Accelerated Amigas

We  strongly  advise  using  an  accelerated  machine with Vistalite.  On an
unaccelerated  machine,  renderings  can  take from several hours to several
days,  depending  upon  the  complexity of the rendering.  On an accelerated
machine  (68040/25 MHz), renderings can take anywhere from ten minutes for a
relatively  simple  700,000  polygon  image to three hours for a complex ten
million polygon image.

Vistalite Landscapes

All  Vistalite  landscape  (DEM)  files on the disk have the file protection
mode  set  to read only.  This assures that you will not accidently delete a
landscape.    The Protect function on your Workbench allows you to reset the
protection  if you wish.  Set normal protection by typing Protect <filename>
rwed  where  <filename>  is the name of the file you want to change.  Do not
type the < or > characters.

Vistalite Stack Requirements

Vistalite  internally  sets  its  stack  to  50000, so you do not need to be
concerned with setting the stack size for Vistalite.

Loading Vistalite from the CLI or a Shell

You  can  start Vistalite from any CLI or Shell by typing Vistalite from the
directory  where  Vistalite  is  located.  You can force Vistalite to load a
particular  landscape by including its device:path/name on the command line.
Some possible examples:

Vistalite ElCap.dem
Vistalite df0:CraterLake.dem
Vistalite dh0:Vistalite/DEM/Mons.dem

You  could  also,  of course, simply type Vistalite and load a landscape via
the Load menu.

Limits of Vistalite's World

Hypercube  Engineering created a fast mixed integer and floating point three
dimensional  engine  for  use  in  Vistalite.  Vistalite displays landscapes
properly  when  the  Camera and Target positions are kept within - 200000000
and  +  2000000000  on all three axes.  Placing the camera or target outside
this  range  or  underground  may result in distorted images or no images at
all.

Speeding Up Vistalite

There  are  two  ways  to  speed  up Vistalite, strategy and brute strength.
After  you  have  used the program for a while, you will learn to "read" the
lower  resolution  settings  in  vistalite  to  see if you are obtaining the
picture  you  want.    When the scene is properly positioned and lighted and
when  you  have set the tree line, snow line and water levels where you want
them,  then,  and  only  then, render the picture at the time consuming full
resolution mode.

Texturizing  the landscape can take a significant amount of time, as can the
Tree function.  We suggest test rendering with these functions turned off to
"prove"  the  scene  and  then,  when you are satisfied with the layout, add
Texturization and Trees.

The  alternative  method for speeding up Vistalite's rendering process is to
add  power  to  your  machine.    Vistalite has been programmed to use every
available computing resource as efficiently as possible.  The time consuming
rendering  process  is  a function of the enormous amount of comptation that
Vistalite  must  do,  not  any  lack  of  optimization of the program itself
Vistalite automatically looks for and uses whatever processing resources you
supply.    When you add an accelerator board or upgrade to a faster machine,
Vistalite  takes  advantage  of  the additional processing power without any
adjustment or request on your part.

Realistic  ray traced CAD objects, detailed three dimensional animations and
realistic  landscapes  are  all  a  part of the emerging software categories
called virtual reality, artificial reality and simulation.  These categories
all  require  immense  computational  capacity but, as the cost of computing
power  continues  to  plummet,  these  types  of  programs  will  become the
standard.    As  a  Vistalite  user,  you  are  pioneering   virtual reality
exploration  and it is admittedly a bit tedious on an unaccelerated machine.
But, looked at another way, it is amazing that this type of rendering can be
done  at all let alone on a personal computer.  Until the advent of Vistapro
and  Vistalite  landscape  renderings of such realism were only available to
users of workstations and supercomputers.

Making the Most of Vistalite

Making  a  stunning  landscape  in  Vistalite requires the combined eye of a
photographer  and  the  artistic sense of a painter, but here are a few tips
which can help improve your first attempts.

Lighting

Experiment  with  the  lighting.    If  the  light is coming from behind the
camera,  scenes  may appear rather flat.  There won't be a strong feeling of
three dimensionality.  You can create dramatic shadowing effects by choosing
the  proper  lighting direction and angle.  With the power of Vistalite, you
can  choose  to  light the scene in ways which could never occur in the real
world or, if you are a purist, you can select the correct solar position for
the  particular  season,  geographic  location  and time of day that you are
portraying.   Virtual Reality Laboratories' Distant Suns planetarium program
(and most other astronomy prograrms) can easily calculate the sun's position
in  order  to  correctly set the light, target and camera position to obtain
maximum realism in your rendering.  If you leave the lighting to chance, you
may  find  that  shadows cover your scene and it does not look as good as it
could.    Setting  the  light  source (the sun) at 45o to 90o to the left or
right  of  the camera gives the best results.  For example, if the camera is
facing  due  north,  placing  the  sun between southeast and east or between
southwest  and  west  usually  makes  the  best  pictures.   Placing the sun
directly  behind the camera usually result in a lack of three dimensionality
and  contrast,  although  there  are  times when this is the desired effect.
Back  lit scenes (e.g., camera facing north, sun shining from the north) can
also yield interesting images.

Snow and Tree Line Setting Considerations

If  you  know  the  normal  range  of  snow line for the season that you are
viewing  and at what altitude the tree line begins, you can use Vistalite to
produce  very  realistic  images.   Tree line varies with latitude until, in
arctic regions, it reaches sea level.  Snow levels vary with the weather and
altitude.

A  little  research at the local library or even listening to the weather on
the  evening  news  can  allow  you  to  increase  the  realism in Vistalite
landscape rendering.  Of course you dont have to follow the real world as an
example.    You  are free to set the tree and snow lin es wherever you wish.
You  may want to see a landscape as it might have looked during the last ice
age  or  as  it  might  look after severe global warming from the greenhouse
effect!

Changing colors

Use  the Color Control Panel (accessed by clicking on the CMap button in the
Control  Panel)  to  change the colors, contrast and exposure with which the
landscape  is  rendered.    Most  landscapes  shipped   from Virtual Reality
Laboratories  have  shades  of  green for lower elevations, brown for middle
elevations  and white for upper elevations.  Try changing the Tree colors to
pinks  and  whites.   This makes them look like flowering fruit trees in the
spring.  Change them to reds, browns and yellows for an autumn scene.

Foreground "fat polys" or "jaggies"

Since  the accuracy of the data limit the detail that Vistalite can display,
some  of  the  foreground  features  will contain '"fat polys" or "jaggies."
Vistalite  builds  all images with polygons millions of polygons per scene.
The  polygons  are  all about the same size but those near the Camera appear
very large on the screen, just as an object very near you looks large, while
when it is far away, it looks very small.

There  are  several  ways  to  reduce this erect.  One of the simplest is to
raise  the  camera  a  few  hundred meters above the ground.  If you use the
mouse  to  position  the camera, it is automatically set thirty meters above
the  landscape.   Since the nearest polygon (the one right under the camera)
is  only  thirty  meters  away  it will look very large (if it is within the
field  of view).  If you raise the camera 300 meters, it will look about ten
times smaller.

A  second  method  is to use the Textur function.  This actually consists of
two  functions,  shading  and  altitude  texturing.   Shading texture breaks
nearby polygons into several smaller pieces and renders each with a slightly
different  shade  giving  them  a  marbleized  appearance.  Altitude texture
fractalizes  the  polygons  into groups of smaller polygons and adds fractal
texture  as  well  as  shading.    Altitude  texture can result in extremely
realistic ground texture, especially for cliffs and desert sand.

Another way to hide foreground polys is to use the Tree function.  Trees are
made of many small polygons and can obscure the large polygons of the ground
underneath them.

A  third  method to hide "fat polys" is to use Gouraud shading.  This blends
the  edges  of  the  polygons  with  each other, eliminating the sharp color
change  from  one  polygon  to  the  next, and provides a beautiful artistic
interpretation  of  the  scene.    This  shades  even  very large foreground
polygons  into oblivion.  Shading Textur and Gouraud shading can be combined
to  generate even more interesting details.  The use of Gouraud shading with
Altitude  Textur  is  not recommended as Gouraud shading will tend to smooth
out the texture added by the altitude texturing.

Sometimes  there  is  a  small  bump immediately in front of the camera that
blocks a large Part of the scene.  Moving the camera a few meters higher may
be  enough  to move the bump out of the field of view, or you might move the
camera far enough forward to get the bump behind it.

A note about aesthetics

Remember,  there  is  no more a "right" way to use Vistalite than there is a
"right" way to use a camera.  A child using a camera or Vistalite may derive
a  lot of knowledge and entertainment from a result which would not please a
more  professional  artist.    Like the natural world it imitates, Vistalite
gives  the  artist an unlimited number of choices for portrayal.  What looks
great to one person may not appear to the next.

Fractals imitate the way nature looks, but they are not the same.  They have
no  knowledge of geology, plate tectonics or erosion.  So, whatever pictures
you  produce  with  Vistalite  will  be  interpretive  be cause Vistalite is
producing  an  artificial  reality  to  begin  with.   The philosophical and
aesthetic  ramifica  tions  of  virtual  reality  construction  are immense.
Vistalite  is  an  early  forerunner  of  a  medium of art and expression as
powerful and unique as photography for creative work.

For  many  years after their introduction, photographs sparked lively debate
about  whether  or  not  they  were  "art." Computer art and virtual reality
simulation seem destined to foment a similar debate.

Exploration with Vistalite

As  a  virtual reality simulator, Vistalite allows you to explore landscapes
that  you  will  probably never be able to explore first hand.  We hope that
most  of  you will have the opportunity to visit a few of the national parks
but it is highly unlikely that any of us, except those who are now children,
will have the chance to tour the caldera of Mons Olympus on Mars.  As we are
able to convert more of the data already available from planetary probes and
undersea explorers, Vistalite will allow you to explore forbidding and alien
landscapes  decades,  or  even centuries, before the first human explorer is
able  to  take tourist snapshots.  By giving its users the ability to wander
about  distant  landscapes,  rendering  true  perspective  pictures of their
choice,  Vistalite  and  later  progeny  will free humanity from its current
boundaries long before such explorations are commercially feasible.

Your own data

Vistalite  can  be  used  to  visualize  any  kind  of  surface which can be
represented  as  a  two dimensional array of integers (of 130 x 130 or 258 x
258).      Scanning tunneling electron microscope data is an example of such
data - think of it as a tiny, tiny landscape!

VISTALITE TUTORIALS
-------------------

To  use  the  following  tutorials, Vistalite must be installed on your hard
drive.    If  you have not already done so, please refer to the installation
instructions on page 1-1.

These  tutorials  have been written with the idea that you will start at the
beginning  and  work your way to the end.  Descriptions and instructions are
more  detailed  at  the  beginning and become less involved as the tutorials
progress.    The  idea  is  that,  through  using Vistalite, you will become
increasingly  familiar  with  the  program.    If you skip sections and find
something  to  be  unclear, you will likely find clarification in an earlier
section.

Tutorial 1: The Basics

Running Vistalite

In  order  to  run  Vistalite,  start  at the WorkBench.  Open the Vistalite
drawer  and  start  Vistalite  by  double  clicking  on  the Vistalite icon.
Vistalite is ready to use when you see a screen with a gray Control Panel on
the right and an empty green topographical map on the left.

A Quick Introduction

When Vistalite is first loaded, it has a flat landscape in its topographical
map.    Although  this  landscape is not very interesting, lets take a quick
look  at  it.    Locate  the  Render  button at the lower left corner of the
Control  Panel.    Move  the  mouse pointer to the Render button.  Press and
release the left mouse button to activate the Render button.

A  sequence  of  status  messages  is  displayed  in  the blue Status Window
immediately  above  the  topographic  map.   For the exact meanings of these
messages,  see  the  chapter  about  The  Vistalite Status Window.  For now,
simply  note  that  Vistalite needs to make some calculations before drawing
the landscape.  After a few seconds, the screen switches to Vistalite's View
screen.    At  first there is a black screen, then Vistalite draws the image
that it has rendered of the landscape in venetian blind style.  Look closely
and  you  will  see a small pyramid in the distance.  At Vistalite's current
settings  (assuming  that you haven't changed anything), the pyramid will be
barely discernible.

It's  not  much  to look at, but you have just rendered your first Vistalite
image.    To switch back to the control panels and topographic map, click on
the left mouse button.  Now let's go on to something more interesting

Loading a DEM Landscape

To  load  a  landscape, position the mouse pointer over the Load menu at the
top  of  the  screen.  Press and hold down the right mouse button.  The Load
menu  drops  down  to reveal several options.  Move the mouse pointer (while
still  holding  the  right  button down) to the first option, Load Vistalite
DEM, and release the mouse button.  A file requestor is displayed.  The file
requestor is used whenever a file is to be loaded or saved.

The Load Vista DEM: button is the file requestor's confirm button.  Clicking
on  the Load Vista DEM: button with the left mouse button or double clicking
on a file name tells Vistalite to go ahead and load the selected file.

The  Abort  button  is  used  to  exit the file requestor without taking any
action.    Clicking  on it with the left mouse button tells Vistalite not to
load  any  file (or save one if the file requestor was opened by a Save menu
option).

The  terms  text  gadget  and  numerical  gadget  are  used  throughout this
tutorial.    A  text  gadget  is a field that accepts text entered from your
keyboard  and a numerical gadget accepts numbers entered from your keyboard.
To  begin entering information into a text or numerical gadget, click on the
gadget  with  the  left  mouse  button.   To abort entry, click on the Abort
button

At  the  center of the file requestor is the filename window.  It displays a
list  of  files  and  directories  (the names with Dir in the right column),
Vistalite  and  Vistalite info files.  Click on the dem directory.  If there
are  more  files than will fit in the window, use the Up and Down gadgets to
the right of the filename window to scroll up and down the list.

You  should  be  looking at a list of files whose names end with .DEM.  Find
the  file  Tutorial.DEM  and double click on it with the left mouse button.
You  could  have typed the file name directly into the Filename text gadget,
but  for small file lists it is faster to double click on the file name with
the mouse.

The  screen  switches  back  to  the  Topographic  Map and Control Panel and
Vistalite loads the landscape.  This may take several seconds.

When Vistalite has loaded the landscape, a topographic view of the landscape
is  displayed  in  the  rectangular  Topographic Map area at the left of the
screen.

The  Topographic  Map  is  colored  by elevation.  Dark greens represent the
lowest  elevations,  browns  represent the middle elevations and gray-whites
the highest.  Move the mouse pointer over the landscape.  Notice that the X,
Y  and  Z  values  in  the  Status Window located below the Topographic Map)
change  as  the  mouse moves.  The X and Y values represents the location of
the mouse pointer on the map and the Z value represents the elevation of the
terrain directly under the pointer.

Setting Camera and target

When  you rendered the flat landscape at the beginning of this tutorial, you
used  the  default camera and target positions.  Let's take a look at how to
move your viewpoint.

Look  at the very top of the topographic map.  There is a small black square
(box)  in the center of the top of the map.  This is your camera position on
the  landscape.  At the very bottom of the map, there is a small black cross
(+) This is your target position (the point at which the camera is aimed).

Look  at  the  X,  Y  and  Z  gadgets located below the Camera button on the
Control  Panel.    The values in these gadgets represent the location of the
camera on the landscape.

To  move  the  camera  position, click on the Camera button.  Move the mouse
pointer over the topographic map to a position where you might like to stand
if  you were taking a photograph of the landscape.  When you have found this
point,  click  once  with  the left mouse button to set the camera location.
Notice that the black square is now at the location that you selected

If  you would like to be above the surface, as if on a tall ladder, click on
the numerical gadget located below the Camera button and to the right of the
Z button.  Enter an altitude (the height of the camera on the ladder).  This
raises  you  above  the  surface of the landscape but leaves you at the same
location.

Now  you  need to tell Vistalite which direction to point the camera when it
takes  a  picture.    Do this by clicking on the Target button with the left
mouse  button,  positioning  the mouse at the point at which you want to aim
the  camera,  then clicking the left mouse button again.  You can change the
vertical  position  of  the  target  in  the same way you did for the camera
position.

Let's  pick  a  point  to look at.  If you have been following this tutorial
from  the  beginning,  the  landscape  Tutorial.DEM should be loaded and dis
played in the topographic map area.

This  landscape  has  four distinct features.  Two at the top and two at the
bottom.    Most  landscapes  do not look like this.  This landscape was made
especially  for  this  tutorial  using  the program TerraForm,avallable sepa
rately from Virtual Reality Laboratories, lnc.

Click  on  the Camera button.  Now click on the blue square in the centre of
the landscape.  Your camera X, Y and Z positions are set.

Look  at  Z  value under the Camera button.  Notice that it is 30.  When you
set  a  camera position with the mouse, Vistalite sets the Z value to thirty
meters above the landscape.  In this case, the landscape under the camera is
at  0  meters  above sea level.  Let's lift the camera a bit higher Click on
the  Z  numerical  gadget beneath the Camera button, enter the number 5 from
your keyboard and press return.  The Z position of the camera is now 530.

To  set  the  target, click on the Target button and then click on the oddly
shaped object at the top left corner of the topographic map.

Viewing Your Camera Position

Before  rendering,  it is often useful to preview the picture as a wireframe
before  it  is actually rendered.  Click on the P button located between the
Target and Camera buttons.  The topographic map will change into a wireframe
preview.    If  you  click  with  the  left mouse button anywhere within the
wireframe  window,  the  target  is moved to the point at which you clicked.
Also, the up-arrow and down-arrow keys on your keyboard control the camera's
zoom.    Press up-arrow to zoom in, and down-arrow to zoom out.  To exit the
wireframe  preview,  click  the  left  mouse  button anywhere outside of the
preview box.

Immediately  below  the  label Poly on the Control Panel, you will find four
buttons  labelled, 2, 4 and 8.  These buttons are used to determine the size
of  the  polygons  which  Vistalite uses to draw the landscape.  Only one of
these  buttons  can  be  selected  at  a  time.  If you simply wish to get a
general  idea of the view from your camera position, click on the 8 button.
This  causes  Vistalite to use large polygons and fewer of them.  The larger
the  Poly  setting,  the  less detail the resulting rendered image has.  The
advantage  of rendering an image with less detail is that it takes less time
to render.

Another  way  to  decrease  rendering time is to click on the LockP button.
This  prevents  Vistalite from calculating a new color palette, which can be
time  consuming.  Before rendering your final image, you will want to unlock
the  color  palette by clicking on the LockP button again, so that Vistalite
will calculate the best colors to use for the image.

Let's  take a quick look at the landscape.  Click on the 8 button.  Click on
the  LockP  button  just to speed things up.  Now click on the Render button
and wait while Vistalite renders the landscape.

As  you  can  see, the landscape looks very blocky, but gives you an idea of
your  camera  positon.    Return to the Topographic Map and Control Panel by
clicking  the  left mouse button.  At this point, you can change your camera
and target positions as described above and rerender the landscape until you
have  a  camera  position  that  you  like.  Once you are satisfied with the
camera  position,  select  a  smaller  Poly  setting and click on the Render
button

Try  rendering  the  landscape  using  each  of the Poly settings.  You will
discover that a Poly setting of 1 can take a bit of time to render.  This is
why  its a good idea to use the larger and faster settings to fine tune your
camera position.

To  abort a rendering in progress, simply click on the Abort button with the
left mouse button.

Adjusting the Camera Lens

Your imaginary camera also has an imaginary lens.  To zoom it in or out, use
the  buttons  labelled  Wide  and  Zoom.    The  Wide  button is the default
selection  and  has  a  focal  length similar to a wide angle lens on a real
camera

Click  on  the Zoom button.  Click on the Render button.  The object (mound)
that the camera is aimed at is now larger.

Click  the  left mouse button to return to the Control Panel.  Near the Wide
and  Zoom  buttons,  there is a numeric gadget labelled FclLn into which you
can type a specific focal length.

Making a Smoother Image

When  rendering a landscape, even at Poly size 1 , there will often be small
triangles in the portions of the image close to the camera.  This is because
the  USGS  data used to make the Vistalite DEM files is made up of elevation
points  that are about thirty meters apart.  When that distance is more than
one pixel wide, that part of the landscape is rendered as a triangular block
There are several ways to hide these blocks in rendered images.

Blend

Blending  smooths  the changes in color from polygon to polygon, causing the
small  polygons  to  be  less  apparent, especially in the distance.  To use
blending  click on the Blend button before rendering an image.  As with many
of  Vistalite's  buttons, the Blend button remains pushed in until you click
it again to disable it.

Dither

There  are two methods of dithering available in Vistalite.  The first blend
the  elevation  colors,  reducing  the sharpness of the snow and tree lines.
This  is  controlled by clicking on the numerical gadget labelled Dither and
entering  a  new  value  from  your  keyboard.   Large values result in more
dithering, small values result in less.

The  second  dithering  method  is  pixel  dithering,  which  mixes slightly
different  colored  pixeis  to  simulate  more  colors  than  the screen can
actually  display.    Pixel  dithering  is  controlled  by  clicking  on the
numerical  gadget  labelled  PixDth  and  entering  a  new  value  from your
keyboard.    Large  values  result in more dithering, small values result in
less.    It  is  possible  to add so much dithering as to make the resulting
image entirely unrecognizable.

Gouraud Shading

Gouraud  shading smooths the boundary between polygons, making it a lot less
apparent  that  they  are  even there.  It also eliminates sharp transitions
from  one  color to another, giving images more of the quality of an artists
rendition.    Enable  Gouraud  shading  by pressing the GShade button before
rendering  an  image.  The button remains pushed in until you click it again
to disable it.

Gouraud shading works well with Shade texturing (see below).

Experiment

Spend  some  time  experimenting  with  the  Vistalite   functions   we have
discussed.    Try  changing the camera and target locations and rendering at
different  Poly  settings  and with different blending functions.  After you
have  a  good  feel  for  the  operation  of  the program, go on to the next
tutorial

Tutorial 2: Making Better Images

Before starting this tutorial, you should have Vistalite running and the DEM
file Tutorial.DEM loaded.  If you do not, refer to Tutorial 1.

Loading an IFF Image

Before we explore Vistalite's features further, let's take a look at a saved
IFF image of the Tutorial.DEM landscape.

Select  Load  IFF  from  the  Load  menu (at the top of the screen).  A file
requestor  appears.  If you are unfamiliar with the file requestor, refer to
the Loading a DEM Landscape section of Tutorial 1.

Find the file Tutorial.IFF.  Double click with the left mouse button on this
filename.    Vistalite loads and displays the IFF image.  The image that you
are  now looking at was created using the Halfdome.DEM landscape and several
of Vistalite's options.

Let's  examine  some of the functions which were used to create this image.
To  return  to  the  Topographic Map and Control Panel, click the left mouse
button.

Image Quality

A  quick  way  to increase rendering quality (and time), is to select one of
the built in Image Quality settings from the IQ menu.

The  tutorial image was rendered using the IQ setting Ultra (once the camera
and  target  positions, pixel dithering, haze density, and lighting had been
set by the user).

Adding Texture

Artificial  detail  can  be  added  to a landscape using the Textur buttons,
located beneath the Textur label.  There are four buttons, only one of which
can  be active at a time.  The buttons are labelled 0, L, M and H (Off, Low,
Medium  and High).  When you click on L, M or H, Vistalite asks which of two
texturing  methods,  Shading  or  Altitude, you wish to use.  Shadingtexture
breaks  the  polygons  in the image into smaller polygons and shades each of
them  separately,  resulting  in smoother transitions of shade and color and
reducing  the  visibility  of larger polygons.  This works well with Gouraud
shading  to  eliminate  the computer generated look and give a more artistic
appearance  to  rendered  images.  Altitude texture fractalizes each polygon
into  smaller  polygons  to  add  texture.    This results in more realistic
images.

If you have already selected either Shading or Altitude texture and you wish
to  change  to the other texturing method, you must turn the Textur function
off  by clicking on the 0 button and then turn it back on by clicking on one
of the L, M or H buttons.

The  higher  the  Textur setting, the more Vistalite breaks up the displayed
polygons into smaller pieces.  Try rendering images using each of the Textur
settings.    Note  that  Altitude texturing can add significant time to your
renderings (expect to wait a while).

Setting the Timber Line

Locate  the  TreeLn  numerical gadget.  The number in this gadget represents
the  timber  line,  the  elevation  above  which  there are no trees.  As in
nature,  the timber line is a fuzzy value.  The Dither function controls how
fuzzy  this  value is (for more info on the Dither function, see the Control
panel  chapter).  Some trees will appear above the timber line and some bare
areas will appear below it

A  timber line elevation can be entered into the TreeLn numerical gadget, or
you  can  use  the  TreeLn  button to set the timber line by clicking on the
TreeLn  button and then clicking on the topographic map at a point which has
the desired elevation.

If  none  of  the tree type (0ak, Pine, Palm or Cactus) buttons are selected
Vistalite  does  not actually draw trees.  Instead, it uses the Grass colors
to  color  the  ground.   See the Control Panel chapter for more information
about trees.

Try  rendering  the  current  landscape with different values for the timber
line.

Drawing Trees

Trees  are  time  consuming to draw and can take from two to twenty times as
long to render as the same scene without any trees.

To  render  trees and specify the type of trees to be drawn, click on any of
the tree type buttons (0ak, Pine, Cactus and Palm).

Setting Tree Density

Click  on  the  numeric  gadget  labelled  TreeSz,  and  enter  50 from your
keyboard.   This sets the height of the trees to fifty meters.  Now click on
the numeric gadget labelled TreeDn, and enter a number between 0 and 256.

Setting the Snow Level

The  snow  level  is  the  lowest  elevation  at  which Vistalite covers the
landscape with snow.  As with the timber line, this is a fuzzy value.

The snow level can be entered directly into the numerical gadget beneath the
SnowLn  button,  or you can click on the SnowLn button and then click on the
topographic map at a point which has the desired elevation.

Adding a Lake

To  add  a lake to your landscape, first select a location for the lake.  It
needs  to  be  an  area  of  the landscape which is surrounded by terrain of
higher  elevation.  Move the mouse around until you find the lowest point in
the  surrounding  terrain.    Click on the Lake button and then click on the
landscape  at  an  eLevation slightly lower than that of the lowest point of
the surrounding terrain.  If you seLect a higher point, the lake would spill
over into other areas of the landscape.

Adding a River

The  River  button  is  used  to  create  rivers that flow downhill from the
selected  starting  point,  following  the terrain.  Rivers continue to flow
downhill  until  they  reach another body of water or elevation 0, whichever
comes  first.    Placing  a  river  on  top  of an existing river widens the
existing river.

To create a river, click on the River button and then click on the landscape
at the point at which you wish the river to start.

Changing the Haze Level

The haze level refers to the amount of haze that appears between the camera,
target  and  the  horizon.    With a haze level of 0, the horizon is crystal
clear,  but  you  lose a little of the three dimensional depth of the image.
To  set or change the haze level, click on the HazeDn (haze density) button.
Vistalite  generates  a haze density value based on the distance between the
camera and the target.  You can also enter a value directly in the numerical
gadget immediately below the HazeDn button.  A high haze density adds a very
nice perceptual depth to an image.

Setting the Light Direction

The  buttons  labelled  N,  E, S and W are used to set the most simple light
directions.   They set the direction of the light source (the sun) to north,
east, south or west at 45° above the horizon.

If  you  want  the  light to come from one of these directions, click on the
button  which  represents  the  appropriate  direction.   You can also enter
values  directly  into the Azimth (direction) and Declin (altitude above the
horizon) numeric gadgets.

Shadows

The other button which controls lighting is labelled Shadow.

When  the  Shadow  button  is  selected,  Vistalite  takes  the light source
direction into account to create shadows on the landscape.

Changing Colors

Using  the  Color  Map  controls,  you  can  alter  the  colors to make your
renderings more realistic.  On the other hand, the Color Map also allows you
to  tamper with nature.  Imagine flaming red snow or pink lakes and rivers.
By  altering  the  color  map,  you  can  drastically  change  the look of a
landscape.

Before  changing  colors,  make sure that the LockP button is not selected.
The palette that is locked by the LockP button is not the Color Map.  If the
button appears to be depressed, click on it to raise it.

To  change the colors.  click on the CMap button in the Control Panel.  this
activates  and  displays  the  Color  Control  Panel.  It has two columns of
buttons on its right side labelled with the names of landscape features.  To
the  left  are R(ed), G(reen) and B(lue) slider bars and H(ue), S(aturation)
and  V(alue) slider bars.  To change the color of a landscape feature, click
on  the  appropriately labelled button and use the slider bars to change its
color.

To  accept  the new colors and exit the Color Control Panel, click on the OK
button.    If  you don't wish to keep any of your changes, click on the Quit
button.

At  this  point, you might wish to read over the Color Control Panel section
of  the  Vistalite  User  Manual.    After you have done so, experiment with
different colors.

Saving a Rendered Image

Now  that you know how to create beautiful and bizarre images, the next step
is saving your masterpiece for viewing at a later date.

Using  the  techniques covered in earlier sections, render an image that you
would  like  to save.  Select Save IFF from the Save menu.  In the resulting
file  requestor,  click on the Filename text gadget and enter MYPIC.IFF from
your keyboard .  Now click on the 0K button.  Your picture will now be saved
and  can  be viewed using the Load IFF menu item or by using any Amiga paint
or viewer program.

VISTALITE MENUS
---------------

If  you  are  not  familiar with how to use menus on the Amiga, click on the
right  mouse  button  when  Vistalite  is displaying it control screen.  Con
tinue  to  hold down the right mouse button and move the crosshair to one of
the  menu  buttons.  Continuing to hold down the right mouse button, drag it
down  the  menu.    Notice that it illuminates various selections.  Continue
holding  down  the  button  until  you  illuminate the menu item you wish to
choose.  Release the mouse button to select that item.

There  are  seven  menus  in  Vistalite:  the  Project  menu, which controls
printing  and  supplies  information  about  the  program; the Load and Save
menus,  which  control  loading and saving of files; the GrModes menu, which
Controls  the  display  and monitor modes that are available with Vistalite;
the  Script  menu,  which  controls  script creation and execution: the CMap
menu, which allows you to quickly change Vistalite's color map for different
seasons, terrain and rime of day; and the IQuality menu, which allows you to
choose predefined image quality settings.

Note:  Many of the following menu items involve the use of a file requestor.
The  Vistalite  file  requestor  contains  a  space to enter the name of the
directory  where  you keep files of the given class (i.e.  the DEM directory
for landscapes, or the Pic directory for IFF images), a window contain ing a
partial  listing  of  the content of that drawer and buttons to the right of
the window for scrolling the contents of the window, a Space for the Name of
the  file  you are worklng with, and a list of common device names where you
are likely to find the drawer (i.e.  DH0:, RAM:).

VISTALITE FILE REQUESTOR

Project Menu

Print

The  Print  menu  item allows you to export Vistalite renderings directly to
your  printer.  It prints whatever is on Vistalite's View screen, so you can
use  Load  IFF to load an image into memory and then use Print to send it to
your printer.

About Vistalite

The  About  Vistalite  menu  item tells you about the program Vistalite, the
authors and the publisher

About Landscape

The  About  Landscape  menu  item  tells  you  about  the   currently loaded
landscape,  including  the  file name, the landscape name, and any available
comments  about  the  landscape.    This  information  comes from the header
contained  at the beginning of Vistalite's Landscape files.  If you generate
a  fractal  landscape and save it, the header will contain information about
the  fractal  setting  used to generate the landscape, which you can use for
your own future reference.

About Image

The  About Image menu item tells you about the image last rendered including
the number of polygons used and the time it took to render.

Quit

The  Quit menu item closes down Vistalite and returns you to the WorkBench.

Load Menu

The  Load  menu  allows  you to load a Vistalite DEM landscape file or image
file.  The Directory name in the file requestor is the name of the drawer in
which you keep your Landscapes or images.

Load Vistalite DEM

The  Load  Vistalite  DEM  menu  item  allows  you  to  load a Vistalite DEM
landscape  file  into  Vistalite.  This can be a landscape that comes on the
Vistalite  disk,  a  landscape that you have previously saved or a landscape
from  a  Vistalite  expansion disk.  Note that the Landscapes that come with
Vistalite  and  those  that  are  on the Vistalite expansion disks are write
protected  to  avoid  the  possibility  that  they  will   accidentally   be
overwritten by a Save Vistalite DEM command.  To unprotect these images (you
probably  will  never need to do this), type Protect <landscape>.dem rwed at
the  CLI  or  SHELL  prompt,  replacing  <Landscape>  with  the  name of the
Landscape you wish to unprotect.

Vistalite can also load normal Vistapro DEMs, averaging every four points on
the Vistapro map to make a single point for Vistalite's internal map.

LoadIFF

The Load IFF menu item loads standard Amiga IFF files.

Save Menu

The  Save  menu  allows you to save a Vistalite DEM or rendered image file.
The  Directory Name in the file requestor is the name of the drawer in which
you  want  to save your file and the Device is the disk where this drawer is
located.  You might use something like Work;Vistalite/Pics.

Save Vistalite DEM

The  Save  Vistalite  DEM  menu item allows you to save a randomly generated
fractal  landscape  as  a Vistalite DEM landscape file.  The saved file will
not  contain surface features such as lakes and rivers.  If you open the DEM
file  to  work  on  it again at a later date, you must recreate any lakes or
rivers  that  you might have placed on the landscape before saving it.  Save
Vistalite  DEM  does  save  the  ColorMap  currently  being  used   with the
landscape.

Save IFF

The Save IFF menu item saves an image in standard Amiga IFF format using the
current  settings of the GrModes menu.  You can load these images into paint
programs  such  as  DPaint  IV  or Brilliance.  The picture saved is the one
currently  on the View screen.  This is usually the scene that has just been
rendered or redrawn.

GrModes Menu

320x200
The  320x200  menu  item  sets  the  current  image size to 320x200, lo-res,
non-interlaced mode.  On PAL machines, this menu item is 320x256

640x200
The  640x200  menu  item  sets  the  current  image size to 640x200, hi-res,
non-interlaced  mode.    You  will  be  warned  if  HAM,  EHB Or 32-color is
selected,  as these modes are not compatible with hi-res on most Amigas.  ON
PAL machines, this menu item is 640x256.

320x400
The  320x400  menu  item  sets  the  current  image size to 320x400, lo-res,
interlaced mode.  On PAL machines, this menu item is 320x512.

640x400
The  640x400  menu  item  sets  the  current  image size to 640x400, hi-res,
interlaced mode You will be warned if HAM or EHB is selected, as these modes
are  not  compatible with hi-res mode on most Amigas.  On PAL machines, this
menu item is 640x512.

On  machines  with  Multiscan screen mode enable, only 640x480 is available.
On  machines  with  Euro  72 screen mode enabled, only 640x400 is available.
This is due to the AmigaDOS restriction on screen size in these modes.

16 color
The  16  color  menu  item sets the color palette to 16 colors.  You will be
warned if you are in lo-res mode, since 16 color mode requires hi-res.

32 color
The  32  color  menu  item sets the color palette to 32 colors.  You will be
warned if you are not in lo-res mode, since 32 color mode requires lo-res in
order to function.

EHB
The  EHB  menu  item  sets the color palette and screen to Extra Half Bright
(EHB)  mode.   EHB mode may not be available on some older Amigas.  You will
be  warned if you are not in lo-res mode, since EHB requires lo-res in order
to  function.  This mode will not function on some Amiga 1000's which do not
have EHB capability.

HAM
The HAM menu item sets the color palette and screen to Hold and Modify (HAM)
mode.   You will be warned if you are not in lo-res mode, since HAM requires
lo-res  in  order  to  function.    HAM mode displays up to 4096 colors in a
single image

HAM8
The  HAM8  menu  item sets the color palette and screen to HAM 8 mode.  This
requires  version  39  or  newer of AmigaDOS and an AGA equipped Amiga.  You
will  be  warned  if  the  AGA chipset is not detected.  HAM8 displays up to
256,000 colors on an AGA equipped Amiga.

256 Color
The  256 color menu item sets the color palette and screen to 256 color mode
This  requires  version  39  or newer of AmigaDOS and an AGA equipped Amiga.
You will be warned if the AGA chipset is not detected.

Show Render

The Show Render menu item allows you to watch Vistalite render images on the
View  screen.    The  default color palette is used during rendering and the
image  is  updated  to  the  final palette when rendering is complete.  This
function slows down the rendering process by a factor of two.

Script Menu

Vistalite's  scripting  controls allow creation of multiple unattended views
of  a  landscape.    The  most  common  use  for  scripts is the creation of
animations.    Scripts  are  lists  of camera and target positions which are
landscape  independent.    You can use the same script for several different
landscapes  or  you  can  change  the  settings  for  the  current landscape
re-executing  the  script.   Script control allows changes to be made to the
landscape without having to rebuild the script every time.  For instance, if
you  want  to  change  the  light  source direction, or if you want to see a
landscape from several views with and without water, all that you have to do
is make the appropriate changes and execute the proper script.

Generate

The  Generate  function  allows  you  to  make  a quick linear path from the
current camera position to the current target position.  This is most useful
for  generating  simple straight-line paths for animations.  When you select
this Option, Vistalite asks for the name of the script file to generate.  It
then  asks  for  the  number  of frames that you want in the script.  If the
camera  is 1000 meters from the target and you select 100 frames, the camera
will  move  10 meters closer to the target in each frame.  The Bank, Heading
and Pitch remain constant (the camera continues to point at the target).  If
you  select  the name of an existing file, Vistalite will ask if you want to
delete  the  file or abort the operation.  We recommend putting script files
in  a  script subdirectory, usually Work:VISTALITE/SCRIPT.  For more complex
scripts,  you  can  use  MakePath,  a  stand-alone script generation utility
available from Virtual Reality Laboratories.

Create

The Create menu item makes a new script.  When Create is selected, Vistalite
displays a file requestor from which you select the device where you want to
save  the  script,  the drawer you want to put the script in and the name of
the script.  If you attempt to create an existing file, Vistalite overwrites
that  file.    After  the  script name is entered, Vistalite creates a blank
script file and opens it for use with the Add option.

Open

Open  retrieves  a  previously  created file for appending new frames.  When
Open  is selected, Vistalite displays a file requestor from which you select
the script to open.

Add

Add  appends  the  current Camera and target positions to the script that is
currently open.

Preview

The  Preview  menu  item  allows  you  to see the path that your script will
follow on the topographic map.  When Preview is selected, Vistalite displays
a  file  requestor  from  which  you  select  the  script to preview.  After
selecting  the  script, you are given the choice of previewing in 2-D or 3-D
mode.  In 2-D mode Vistalite draws a sequence of dots on the topographic map
to  indicate  each  camera  location  (one dot for each frame).  In 3-D mode
Vistalite renders a real time, 3-D wire frame preview in the topographic map
area.

Execute

Execute  causes  Vistalite  to execute a selected script, creating a picture
for  each  frame  in  the  script file.  When Execute is selected, Vistalite
displays  a  file  requestor  from  which  you select the script to execute.
After  the script is selected, Vistalite displays another file requestor for
you to specify a name for the animation file being created.

Anim Mode

VANIM

Vistalite does not directy support the Amiga's standard ANIM format, it uses
its  own  proprietary  animation format, VANIM (Vistalite ANIM).  Our format
has both advantages and disadvantages.

The advantages are:

VANIM animations limit you to available disk space, not memory size.  If you
have an 800MB disk you can play an 800MB animation.

Each frame has its own color palette.

You  can  play  animations backward, forward, single-stepped, jump- stepped,
etc.

The disadvantages are:

Animation files are about twice as large as regular Amiga ANIM files.

Playback  of  animations with large frame sizes can be as slow as two frames
per second.

CMap Menu

The  CMap  menu allows you to quickly change colors for season, terrain type
or  sky  without  having  to set all of the colors individually in the Color
Control  Panel.    Selectons are available for Spring, Summer, Winter, Fall,
Sunrise,  Sunset,  Daylight,  Desert  and  Mars.    The   Sunrise and Sunset
selections  affect only the skyhaze color and do not change any of the other
color  settings.    So,  you  can select Summer and then Sunset for a summer
sunset.

IQuality Menu

The  IQuality  menu offer a quick way to set functions on the control panels
to  predefined  settings,  resulting  in  different  levels  of  quality for
rendering images.  The Low, Medium, High and Ultra menu items are mainly for
casual  users  so  that they won't have to search through the manual for the
most frequently used settings at the various image quality levels.

Low
The  Low  menu  item  sets  Vistalite  up  for  fast  but  relatively  crude
renderings.    It  is  useful for test renderings to check camera and target
locations.

Medium
The Medium menu item sets Vistalite up for medium resolution renderings.  It
is useful for slower machines or for "proof of concept" renderings.

High
The  High  menu  item  sets  Vistalite up for high resolution renderings and
results  in good quality images.  It is not quite the best quality possible,
but it is faster than the absolute best settings.

Ultra
The  Ultra  menu  item sets Vistalite up for the absolute highest resolution
renderings  possible.   It can take hours to render an image, even on a fast
machine, but the result is worth the time it takes.

CONTROL PANEL
-------------

CONTROL PANEL AND TOPO MAP

The  Topographic  Map  on  the  left  side  of  the main screen represents a
landscape  area  which has been loaded into Vistalite.  The small "+" symbol
on the map is the target.  The small "box" symbol is the camera.

Target

The  Target  represents  the  point  at  which  you  are   aiming Vistalites
hypothetical camera.  Its location is measured in meters from the lower left
corner  of  the  topographic  map and in meters above sea level.  Select the
Target  button, then place the mouse pointer anywhere over the landscape and
click  the  left  mouse  button  to set a new target position in the X and Y
directions.    The  Z,  or  height,  value  is  set  to the elevation of the
landscape  at  that  X,  Y  coordinate.   That is, the Z value of the Target
represents  the  actual  elevation  of  the  landscape at that point.  As an
alternative,  you  can  place  the  target precisely by entering coordinates
directly  into  the X, Y and Z value windows.  To change a value, select the
appropriate  value  window  by  clicking  the left mouse button in the value
window.    Use  normal  editing  techniques  to  change  the   window values
(Backspace, Delete, etc.).  See also Locking Functions.

Camera

The  Camera  represents the location of a hypothetical camera used to take a
scenic  picture.    Its  location  is measured in meters from the lower left
corner  of  the  topographic  map  and  in  meters  above  sea level.  The X
coordinate  is  from left to right on the topographic map.  The Y coordinate
is  from  bottom  to  top of the topographic map, and the Z coordinate is in
meters  above  sea  level.  The lines radiating out from the camera position
are  the  field  of  view lines.  They represent the approximate area of the
landscape that will be rendered with the current lens settings.

To  set  the  camera  position,  select  the  Camera button, place the mouse
pointer anywhere over the topographic map and click the left mouse button to
set  a  new  camera  position  in the X and Y directions.  The Z, or height,
value  changes  with  the  elevation  of  the landscape.  The Z value of the
camera is set to an elevation 30 meters above the landscape.  Alternatively,
you can place the camera precisely by entering coordinates directly into the
X,  Y  and Z value windows.  To change a value, select the appropriate value
window  by  clicking  the  left  mouse  button inside the value window.  Use
normal  editing  techniques  to change the window values (Backspace, Delete,
etc.).  See also Locking Functions.

Locking Functions

Other  tools  that you can use with both the Camera and Target functions are
the  X,  Y and Z locks.  Use the locks when you want to constrain the target
or  camera from moving in one or more directions.  For instance, if you want
to  move  the camera to a new location on the landscape without changing its
altitude,  depress  the Z lock and then click on a new camera location.  You
will  see  that  the X and Y coordinates of the Camera have changed but that
the  Z  value has remained unchanged.  Of course there are two other ways of
achieving  this same result: you could simply type the new X and Y locations
into  the  Camera X and Y string gadgets or you could click the mouse on the
new  camera  location (with the Z lock not set) and then type in the desired
altitude.  Vistalite constrains both camera and target X, Y, and Z values as
long as the locks are depressed.

P

The  P  button  shows you what the camera sees as a wire frame perspective.
This is useful for previewing the features your picture will contain.  While
in  the  wire  frame  preview  mode,  you  can  rotate (point) the camera by
clicking  where  you  want  the  camera  to  point in the preview area.  For
instance,  if  the camera is pointing at the top of a mountain and you would
rather look at the base, place the mouse pointer at the base of the mountain
and  click  the left mouse button.  Vistalite rotates the camera and renders
the new wire frame view.

WIRE FRAME PERSPECTIVE VIEW

You  can  also adjust the focal length of the camera lens by pressing the up
arrow  key  to zoom in a little or the down-arrow key to zoom out a little.
Each time you press the key, the camera zooms in or out a little more.

While in the wire frame preview mode you can not access the Control Panel or
the menus.  To exit wire frame preview mode, click anywhere outside the wire
frame preview area and the topographic map will return.

dR

DR displays the distance in meters between camera and target.  This distance
is  the radius from the target.  You can use this value to step closer to or
away from the target, just as you might do when taking a photograph.

When  you  type  in a new distance value, Vistalite changes the cameras X, Y
and  Z  coordinates  to  match  the desired distance as well as it can.  The
Bank, Heading and Pitch values are not changed.

dX

DX displays the difference between camera and target X coordinates.  You can
change  this  value  by  entering  a  new value in the dX numerical gadget.
Changing  this  value  moves  the  camera  to reflect the new distance.  The
Heading  and  Pitch of the camera may also change to keep the camera pointed
at the target.

dY

DY displays the difference between camera and target Y coordinates.  You can
change  this  value  by  entering  a  new value in the dY numerical gadget.
Changing  this  value  moves  the  camera  to reflect the new distance.  The
Heading  and  Pitch of the camera may also change to keep the camera pointed
at the target.

dZ

DZ displays the difference between camera and target Z coordinates.  You can
change  this  value  by  entering  a  new value in the dZ numerical gadget.
Changing  this  value  moves  the  camera  to reflect the new distance.  The
Heading  and  Pitch of the camera may also change to keep the camera pointed
at the target.

The following descriptions use an airplane as a model.

Bank

Bank  controls  the  rotational  angle  of the camera along its longitudinal
axis.    Imagine  an  airplane  floating  in  space.    You can describe the
longitudinal  axis  as an invisible line drawn from the tail of the airplane
to  its nose.  A rotation that causes one wing to dip and the other to raise
is a rotation around the longitudinal axis.  A positive rotation around this
axis  causes  rotation in a clockwise fashion.  The left wing raises and the
right  wing  lowers.    Note  that  when  the  plane  (camera)  banks in one
direction, the view that is rendered appears to have rotated in the opposite
direction.

Head

Head describes the rotational angle of the camera around its Z axis relative
to  the landscape.  Imagine an airplane floating in space.  You can describe
its  Z  axis as a line drawn from the top of the airplane through its middle
to  its  bottom.    A  rotation around this axis causes the airplane to turn
right  or  left.    Positive  rotation  causes the airplane (camera) to turn
right.

Pitch

Pitch  is  the  rotational  angle  of the camera around its wing axis.  Once
again  imagine  an airplane floating in space.  A line drawn from the tip of
one wing to the tip of the other describes the wing axis.  A rotation around
this  axis  causes  the  airplane's  nose  to move up or down, with positive
rotation causing the nose to go up.

CMap

Select the CMap button to display and activate the Color Control Panel.  See
Color Control Panel for information about specifying colors.

LockP

The LockP button locks the color palette.  Normally, Vistalite generates the
best  color  palette  that  it can for each image based on the terrain it is
rendering.    This can cause some flickering in animations as the same areas
change  color  slightly  from frame to frame.  By locking the color palette,
you  guarantee  that  the  colors  will  be  consistent between frames of an
animation  When  you  select  the LockP button, the palette is locked at the
current  settings.    You should generate a typical frame before locking the
palette  to  ensure  that the palette contains a reasonable cross-section of
colors.

SeaLvl

By  setting  the  sea level, you can sink the landscape into the sea to that
level.    All  points  below  this level become sea level (0 meters) and all
points  above  this  level  have that value subtracted.  For example, if you
select  1,000  meters  as  sea  level,  all points below 1,000 meters become
0,2,000 meters becomes 1,000 meters, 3,000 meters becomes 2,000 meters, etc.


Vistaiite asks if you would like to erase rivers and lakes (if present) when
it  generates  a  new  sea  level  and if you would like to add waves on the
ocean.  Vistalite will need to color and shade the landscape again.

Vistalite  has  a button which allows you to specify a new sea level.  Click
on  the  SeaLvl  button  and  then  select  the  level  by  clicking  on the
topographic map at the point that you want the new sea level to be.  You can
also  specify  the  sea level explicitly by typing the value into the string
gadget immediately below the SeaLvl button.

TreeLn

The  TreeLn  button is used to set the timber line, the altitude above which
there are no trees.  The timber line is a "fuzzy" value.  Just as in nature,
some  trees  will appear above the tree line and some bare areas will appear
below  it.    Vistalite's  artificial intelligence (AI) rules compensate for
features  of  the  landscape.   Trees generally will not cover the face of a
cliff  even  though  the entire cliff may be below the tree line.  Trees may
grow upward in the bottom of a valley (more water is available at the bottom
of a valley) and a ridge will tend to be devoid of trees (ridges tend to dry
out from exposure to the wind.)

If  none  of the tree type buttons (Pine, Oak, Palm, Or Cactus) are selected
in  the  Control  Panel, Vistalite does not actually draw the trees, it just
uses  the  grass colors, Grass 1 through Grass 4 on the Color Control Panel,
to color the ground.

Use  the  TreeLn button to select the tree level.  Depress the TreeLn button
and  then  click  on the topographic map at a location which has the desired
altitude.    You can also specify a tree level numerically by typing a value
into the string gadget located below the TreeLn button.

SnowLn

The  snow level is the lowest elevation in meters where Vistalite will cover
the  landscape  with  snow.    The  artificial  intelligence  (AI)  rules in
Vistalite  use  this  value  to  calculate  where  to  use  the snow colors.
Vistalite  compensates  for  cliffs, ridges, valleys, rivers and lakes in an
attempt  to  mimic  natural  snow  cover.   Snow colors don't have to be the
colors  of  real  snow.  You can use any colors you like.  Just keep in mind
that  the snow colors will be placed on the landscape following the AI rules
for  snow.    For instance, you can set the snow colors to shades of grey to
make  mountain  tops  look  like  barren  rock.  The barren rocky areas will
appear to flow down into valleys just as snow would.

You  can use the SnowLn button to select the snow level.  Depress the SnowLn
button  and  then  click  on the topographic map at a location which has the
desired  altitude.  you may also specify the snow line numerically by typing
a value into the string gadget located below the SnowLn button.

HazeDn

In the real world, the farther away an object is, the more it is occluded by
the atmosphere.  The haze function in Vistalite simulates this effect adding
to  the  three dimensional feel of the resulting image.  You can specify how
thick  the  haze  is by changing the HazeDn value.  (You can also change the
color of the haze see Color Control Panel.) Enter the haze value by typing a
number  in  the  string  gadget  below  the  HazeDn  button.    A value of 0
completely  eliminates  the  haze  effect; small values (less than 100) give
very  little  haze,  medium  values  (100  - 1000) give medium haze and high
values (greater than 1000) create very thick fog.

You  can  also automatically calculate the haze value by pressing the HazeDn
button.  Vistalite will generate a value based upon the distance between the
camera  and  the target.  The closer the two are, the thicker (higher value)
the  haze.    We tried to arrange it so that setting the haze value this way
generates haze that first becomes significant at distances about the same as
that between the camera and target.

Lake

Lake  generation  adds lakes to a landscape.  Select the Lake button.  Then,
using  the  mouse,  place  the  pointer on the landscape at the desired lake
level  and  click  the  left  mouse  button.   For example, if you place the
pointer  in  a  shallow valley at 2,100 meters, water will begin to fill the
valley  until  it  reaches the 2,100 meter level, as it would in nature.  If
there  is  any  portion along the edge of the valley that is below the 2,100
meter  level,  water  will  spill out of the valley and begin to flood other
parts of the landscape.  This may not be the desired effect and it should be
kept  in  mind  when using the Lake function.  If there is uncertainty about
the  height  of any portion of the landscape, you can move the mouse pointer
around  any  suspect  areas and watch the Z value on the status line to find
the  lowest  point  in  the  pass to determine the maximum safe altitude for
creating the lake.

To  create  a lake, press the Lake button and then click on a starting point
on the topographic map.  Vistalite opens a requestor indicating the level to
which  the  lake  will fill (the altitude of the point you clicked on).  You
can  change  the  level  to a different value if you wish.  You will see the
lake  being created on the topographic map in black.  Once the lake has been
completed the black lake is redrawn in blue.

River

Vistalite's  River  function  creates  rivers  which  flow downhill from the
selected  starting  point.   If a river reaches a depression it slowly fills
the  depression,  creating  a  pond  or lake, until it overflows.  The river
continues  to  flow  down hill until it reaches the ocean or the edge of the
topographic  map.    Although  you  can  always  fill a lake using the River
function, it is generally faster to fill lakes using the Lake function.

To create a river, press the River button and then click on a starting point
on  the  topographic  map.    You  will  see  the river being created on the
topographic  map  in  black.    Once the river has been completed, the black
river is redrawn in blue.

If  you  start a river on an existing river or lake, the river will continue
until  it  reaches  sea level or the edge of the topo map.  A new river (one
started where there was not a river or lake to start with) will also stop at
any  existing  water.  This allows you to create many tributaries to a river
without  the  main  river  getting very wide and deep.  If you want the main
river  to  get  very  wide,  start a new river on top of the old one as many
times as you like.  It will grow wider with each iteration.

You  will  generally want to start rivers at the head of a valley, but it is
possible to start a river anywhere on the topographic map.

Clouds

The  Cloud  function  generates  a  new  cloud  map, or cloud formation, and
enables cloud rendering.  Clouds look best in 256 color, HAM and HAM8 modes.

Stars

Vistalite  can  generate  stars  in  the night sky.  To enable this feature,
select  the  Stars  button from the Control Panel.  You will be asked if you
would  like  double  width  stars  and  then if you would like double height
stars.    This makes the stars brighter and more visible in HiRes modes.  To
disable  the stars function, select the Stars button again.  When you enable
stars,  Vistalite  displays  them  in  the  sky whenever it renders a scene.
Vistalite  automatically changes the sky color to black and changes the haze
and  sky  haze  colors  to  dark  shades.    The  star patterns are randomly
generated  and  bear  no  resemblance  to  the real night sky as viewed from
earth.    Stars  may  not  show  up  well in LoRes and HAM modes (because of
antialiasing), unless you use double width and/or double height stars.

Some recommended settings to use with stars enabled:

Item                Red        Grn        Blu
Sky                  00         00         00
Haze                 10         10         10
SkyHaze              10         10         20
Haze value         (250)

For a sundown effect:

Item                Red        Grn        Blu
Sky                  00         00         30
Haze                 10         10         10
SkyHaze              60         00         00
Haze value         (250)

Pine, Oak, Palm and Cactus

The  Tree Type buttons cause Vistalite to render the selected type of trees,
randomly  spaced in the flat (less than 30° slope) areas of the landsccape.
Only one tree type can be selected at a time.

TreDn

The number of trees drawn on the rendered landscape can be adjusted with the
TreDn  value,  ranging  from 0 to 255.  The higher the value, the more trees
are rendered and the longer it will take to render the image.

TreeSz

The  TreeSz  value  determines  the  approximate height, in meters, of trees
rendered on the landscape.  The trees will not all be of the same height, as
a random value is added to the TreeSz.

FclLn

The  Fcl  Ln  value  is  similar  to  the focal length of a real camera.  It
represents  the  width  of the field of view or the amount of magnification.
The lower the Fcl Ln value, the wider the field of view.  The higher the Fcl
Ln  value, the narrower the field of view and the greater the magnification.

The  lowest  valid  Fcl Ln value is 1.  This is an extremely wide angle lens
with  severe spherical distortion.  Values below 8 are generally impractical
but  sometimes  interesting  to  try.   You can set the Fcl Ln to as high as
30000,  but  such  high  numbers are only useful when the camera is very far
from  the  landscape (a million meters or so).  You will probably use Fcl Ln
values from 16 to 100 in normal situations.

The  field  of view for the current Fcl Ln value is shown on the topographic
map as lines radiating out from the camera.

Wide

The  Wide  lens gives a 90° field of view.  It allows you to see a wide area
with  minimal  spherical  distortion.    The  wide  lens  has a Fcl Ln value
(similar to the focal length of a real camera) of 16.

Zoom

The  Zoom lens has about half the field of view of the wide lens (about 45o)
or  you may think of it as having twice the magnification.  It allows you to
zoom in on the target.  Very little distortion is noticeable.  The Zoom lens
has a Fcl Ln value of 32.

Poly

At  its  finest resolution, Vistalite produces 16,900 polygons for each land
scape  it  renders.    The  Polygon  Size  function  controls   the relative
coarseness of landscape images rendered by Vistalite.  A size of 8 generates
1/64th  as  many polygons (1/8th on each axis) as a size of land they are 64
(8 x 8) times as large.  That is, a rendered landscape can consist of 16,900
size  1 polygons, 4,096 size 2 polygons, 1,024 size 4 polygon, or 256 size 8
polygons.    You can use the larger polygon sizes to generate quick previews
of  landscapes.    Then,  when you are satisfied with your camera and target
placement,  use  smaller  polygons.  The smaller the polygons, the longer it
takes  to  render the image.  The larger the polygon size selected, the less
detail  that will show up in the image, because Vistalite is displaying only
a  fraction of the full data.  The lower resolutions (higher poly number, ie
4  or  8)  are  useful  for quick test renderings to check the landscape for
color, light placement and exposure settings.

Dither

Vistalite generally colors landscapes by altitude.  The lowest altitudes are
colored  with  Grass  1 through Grass 4 colors, middle altitudes are colored
with  Bare  1  through Bare 4 colors, the highest altitudes are colored with
Snow 1 through Snow 4 colors.  Each of the 16,900 triangles that make up the
landscape  is  assigned  a  color  based  on  its altitude and several other
factors.

The  Dither  value  determines the "fuzziness" of the division between color
bands.   A setting of 0 makes the tree and snow lines very sharp boundaries.
The  default  setting  of  128  gives  a moderate amount of dithering of the
colors.    A large value, like 1000, makes the colors so dithered that there
is  no  visible relationship between altitude and color.  To set this value,
click  the  mouse pointer on the Dither string gadget on the Control Panel.
Change the number from the keyboard.  Useful values range from 0 to 1000.

Textur

O L M H

Vistalite can add additional texture to polygons near the camera by breaking
them into smaller pieces and coloring each piece a slightly different shade.
This  adds  artificial  detail  to  nearby  areas.  There are four different
levels of texturing: Off, Low, Medium and High.  They are selected by the O,
L,  M  and  H buttons below the Textur label.  Pressing one of these buttons
brings up a panel which gives you a choice of Shading or Altitude texturing.
The  higher  the  detail level, the longer a picture takes to render but the
more detailed it will appear.

Shading  texture  breaks  nearby  polygons into several smaller polygons and
shades each polygon separately, giving the landscape smoother transitions of
shade  and  color  and  making large polygons less visible.  Shading texture
works  well  with  Gouraud shading to eliminate a computer generated look in
landscapes and give more of an "artistic" appearance.

Altitude texture fractalizes the polygons into groups of smaller polygons to
add  texture.    These  smaller  polygons  are  then individually shaded and
colored.   Altitude texture produces the most realistic looking landscapes.
Gouraud  shading  is  not recommended to be used with Altitude texture as it
tends to smooth out the fractal effect.

PixDth

Dithering  at the pixel level increases the apparent number of colors in the
display.    Vistalite  uses  a  dithering method which allows you to set the
amount of dithering used within the display.  It can be set anywhere from no
dithering to so much dithering that you no longer recognize the picture.

Random

Random  landscape  generation allows creation of a vast number of completely
artificial  landscapes.   Vistalite support over four billion random fractal
landscapes.    Each  different number in the Fractal Landscape Number gadget
below  the  Random button represent a different landscape.  You can use both
positive  and  negative  numbers.    A  number  such as -1,231,541 creates a
different  landscape  than  its  positive  counterpart,  +1,231,541.  Select
Random  on the Control Panel.  A new number appears in the Fractal Landscape
Number gadget below the Random button and Vistalite proceeds to create a new
landscape.    After a time, depending on the speed of the system running the
program,  a  new  landscape appears.  If this landscape is one which you may
want to use again, be sure to write down the number so that you can generate
it  again, or save the landscape using the Save Vistalite DEM menu item.  To
recreate  a  particuIar  landscape, simply reenter its number in the Fractal
Landscape  Number gadget and Vistalite will create the same landscape again.
This  conserves  disk  storage  space.    You  may enter any number into the
Fractal  Landscape  Number  gadget  and  explore landscapes in this fashion.
Various  methods  include  using  special  dates  such as birthdays (without
hyphens  or  slashes,  ie  52262  rather   than   5-22-62),   holidays   and
anniversaries.  Keep a list of numbers for those landscapes that prove to be
interesting so that you can share them with other owners of Vistalite.  Like
the  fingerprints  of  the  four  billion  inhabitants  of this planet, some
Vistalite  scenes may look similar but, upon closer examination, each one is
individual  and  distinctive Fractal landscape generation is affected by the
fractal dimension (FrDim) and Fractal Divisor settings.

Fractal Landscape Number

This  string  gadget  (located below the Random button) is used to enter the
number  of the fractal landscape you wish to generate.  It also displays the
random  number  generated  when you press the Random button.  Vistalite uses
this  number  to  generate  fractal  landscapes.    To  enter your own value
position  the mouse pointer over the gadget and press the left mouse button.
The  pointer  disappears.    Type in your number from the keyboard and press
Return.    Vistalite  then  generates that landscape.  Note that the fractal
dimension  and  fractal  divisor  values  are  also  used  to   generate the
landscape.

Island

There are two modes for generating fractal landscapes, Island and Floating .
In  Island  mode the altitude of the four edges of the fractal landscape are
the same.  This allows you to create islands by setting the sea level higher
than  this  edge  altitude.    See  the  SeaLvl  function for details on its
operation.    In Floating mode, the four edges of the landscape are all owed
to  float  -  that  is, they are allowed to vary in altitude.  Floating mode
landscapes  look  like  they  were clipped out of a larger area - similar to
real-world DEM landscapes.

If  the  Island  button  is  depressed,  fractal landscapes are generated in
Island mode, otherwise they are generated in Floating mode.

FrDim

The  FrDim value controls the fractal dimenion (height and roughness) of the
fractal  mountains.    This value is used for subsequently generated fractal
landscapes.    Typing  in  a new value does not affect the current landscape
unless you regenerate it.  The default value is 100.  Larger values generate
taller,  rougher landscapes.  Smaller values generate flatter, smoother land
scapes.

Frctlz

You  can  fractalize  the current landscape to add fractal detail to it.  If
the  FrDim  is  set  to  a  low  value,  the effect of this is to smooth the
landscape.    If  the  FrDim  is  set to a high value, the landscape becomes
rougher.   The Fractal Divisor buttons (1, 2, 4, and 8 immediately below the
Fractlz  button)  control  the scale at which the fractalization occurs.  At
lower values, fractal noise is added only at very small scales the landscape
will  be  basically  the  same  shape,  but  rougher.   At higher values the
landscape  will  start  looking  rougher  at larger scales and may no longer
resemble the original landscape.

Fractal Divisor

The  Fractal  Divisor buttons are the four buttons located below the Fractlz
button.    They  are  labeled 1, 2, 4, and 8.  The values they represent are
used by the fractal generation routines.  When Vistalite generates a fractal
landscape  (after  you  press  Random  or  enter  a  value  into the Fractal
Landscape  Number gadget), it uses the current divisor setting.  The smaller
the fractal divisor, the larger the features of the landscape.  At a setting
of  1,  very  large mountains are generated.  At 8, many small mountains are
built.  For the Fractlz function, the divisor value represents the frequency
at  which  the existing landscape data is sampled in order to generate a new
landscape.  See the section on Fractlz for more details.

NSEW

Use  the  North,  South,  East, and West buttons (labeled N, S, E, and W) to
quickly  set  one  of four "standard" lighting positions.  These buttons are
positioned  so  that  you  can  easily  see  from which direction the sun is
shining.    When  using  one  of  these  positions, the sun is 45o above the
horizon.   Using these pre-programmed directions speeds up the shading phase
of  rendering  when  shadows  are  enabled.   After clicking on one of these
buttons,  the  Sun Vector (the line radiating from the center of the "bull's
eye") changes to indicate the new direction.

Custom

The Custom button allows you to have complete control over the direction and
angle  of  the  light  source.   When Custom is selected, several concentric
circles  are  drawn  in  black  over the topographic map.  These circles are
reference  points for you to use to visually estimate the declination (angle
above  the  horizon)  of  the  sun.    The  circles  are  labeled   with the
declinations  that  they  represent:  75°,  60°  45°,  30°  and 0° above the
horizon.    A  line (the Sun Vector) is drawn from the center of the "bull's
eye"  toward the edge of the landscape.  The direction of the line indicates
the  azimuth  (direction  around the horizon) from which the sun is shining.
The length of the line indicates the declination of the light source.  Think
of  the  Sun Vector as a stick stuck in the center of the landscape which is
pointing  at  the  sun.    Since  the  topographic  map is being viewed from
directly  overhead,  the  longer the stick appears, the closer the sun is to
the  horizon.    If  the  stick  appears  very  short, it is pointing nearly
straight  up.    The  Sun Vector to follows the mouse pointer as you move it
around the screen.  When you have located the desired direction and angle, a
single  click  with the left mouse button locks it in place.  Using a custom
light  source  may  increase  the  amount  of  time required to complete the
shading phase of the rendering process when shadows are enabled.

CUSTOM LIGHT DIRECTION

Azimth

Use  the  Azimth  gadget  to  set  the direction of the sun (in degrees from
South).    Zero degrees is due south, 90° is due west, 180° is due north and
270°  is  due  east.    Note  that  this  differs from the heading, which is
measured from due North, as is common in navigation.

Declin

Use  the  Declin gadget to set the declination, the angle above the horizon,
from  which  the sun shines.  Zero degrees of declination puts the sun right
on  the  horizon, while 90° puts the sun directly overhead.  This is similar
to the way Pitch is measured for the camera.

In  astronomy,  this  value  is usually called altitude (measured in degrees
from  the  horizon)  rather  than declination.  It was decided that the term
altitude  might  be confusing since it is also used to describe the altitude
of  the  camera  (measured  in meters).  Be aware that the usage of the word
declination here is not technically correct.

Rough

The  Rough  gadget  sets  the apparent roughness of the landscape when it is
rendered.    Vistalite accomplishes this by adding a scaled random number to
the  shade  of  each  polygon,  so that some of the polygons are darker than
normal and some are lighter.  By doing this, large flat areas appear to have
a  little  more  detail than they otherwise might.  To set this value, click
the  mouse  pointer  on the Rough string gadget.  Change the number from the
keyboard  and  press Return.  Useful values range from 0 to 300, with higher
values  giving  rougher  appearing  landscapes.  Very large roughness values
result  in  unnatural  shading.  This is used in conjunction with the Textur
function.

Shadow

Vistalite  has  the ability to render landscapes with shadows.  True shadows
are  very difficult and time consuming to render, so Vistalite uses a quick,
less  precise method.  Only the landscape itself casts shadows; trees do not
cast  shadows.    Shadows  are  not cast outside the area of the topographic
data.  Shadows are enabled when the Shadow button is depressed.  The shading
phase requires more time when shadows are enabled.

Blend

Blend  helps  reduce  the coarse texture of distant parts of the landscape.
When  you  select  the  Blend  button,  Vistalite  draws each polygon with a
weighted  average  color  of that polygon and the three polygons that border
it.    This  reduces  the aliasing of distant polygons.  It also reduces the
color saturation of polygons, so its use is optional.

GShade

Gouraud  shading produces smooth looking surfaces without obvious triangles.
It  requires  about 50% more time to render a landscape with Gouraud shading
than  without  it.    Gouraud  shading  gives  a  brush  like feeling to the
landscape,  as  if  an  artist  painted it using oils, rather than the Amiga
playing  with numbers.  Besides altering out large polygons, it adds mood to
the landscape.  The foreground may appear blurry with Gouraud shading.

Render

Clicking  on  the Render button starts the generation of a new picture using
the  current  settings  in  the  Control  Panel.  Vistalite performs several
functions  while  rendering.   It displays its progress at the bottom of the
screen  in  the  Status Window.  For most functions, there is a continuously
updated  status  count  so  that you can monitor Vistalite's progress.  (See
Vista  Status  Window  for  more  information.)  You can abort the rendering
process by pressing the Abort button.

Redraw

The  Redraw  button  redraws  the  image onto the View screen in the current
resolution/mode set by the GrModes menu.  This only works for the image last
rendered and if the image size has not been changed.

Vistalite  uses  two  different algorithms for drawing in HAM mode.  If, the
polygon size is set to either 4 or 8, it employs a crude but fast algorithm.
When  using  HAM  mode,  more HAM artifacting is noticeable at these polygon
sizes.  HAM artifacting is the colored spikes that can appear in a HAM image
at sharp contrast transition boundaries.  If the polygon size is set to 1 or
2,  Vistalite  uses  a  more  precise  method  which  results  in   less HAM
artifacting.

View

When  the rendering is complete, Vistalite automatically displays the image.
If  you have returned to the Control Panel, you can redisplay the image with
the  View button.  If you have used the CMap function or any of the About...
menu  items,  View  shows  that screen.  To redisplay a rendered image after
selecting  one  of  the  About...    menu  items, use the Redraw button.  To
redisplay an image after using the CMap function, you must rerender it.

Abort

The  Abort  button  stops  the  rendering process.  The Abort button may not
appear  to  be pressed when you press the mouse button, but it will still be
active and will abort the current function.

COLOR CONTROL PANEL
-------------------

The  Color  Control  Panel controls palette selection and a variety of other
functions.    This  panel  is  accessed  by  pressing the CMap button on the
Control  Panel.    Both the R(ed), G(reen) and B(lue) sliders and the H(ue),
S(aturation) and V(alue) sliders on the left part of the Color Control Panel
allow you to select and mix colors.  The center part of the panel is devoted
to  those aspects of landscape coloration which are under your control.  The
OK  button  loads your selections and returns you to the Control Panel.  The
various features of the Color Control Panel are described below.

Colors

The  Color  Control Panel is used to change the colors used for Sky, Cliffs,
Snow,  Bare  Earth,  Trees  and Water.  These are the colors of the polygons
that  make  up  the  landscape.   Each of the colors are shaded and faded by
Vistalite as it renders the landscape.

For example, an apple may be a uniform shade of red, but the side that faces
the  light  is  brighter  than the side that faces away from the light.  The
apple  fades  toward  haze color as you move it farther into the haze.  Even
though  there  are  only a few different object colors in Vistalite, each of
the colors may produce hundreds of shades.

Vistalite  maps  Grass, Bare and Snow colors to the landscape fundament ally
by  elevation.    Vistalite gives the lowest elevations Grass colors, middle
elevations  Bare  colors  and high elevations Snow colors.  The same is true
for  each of the four colors within each segment.  The lowest elevations are
ssigned the color Grass 1, slightly higher elevations Grass 2, and so forth.
The designation of colors as Grass, Bare and Snow is arbitrary.

You  can,  for instance, make them all different shades of red for a Martian
landscape,  or  any  colors  desired for an especially bizarre picture.  The
boundary  between  the  different zones is fuzzy.  For instance, setting the
tree  line  at  1000  meters does not mean that everything below 1000 meters
will  be  Grass  and  everything  above it will be set to Bare or Snow.  The
local  shape  of  the  landscape  and  some  random dithering affect all the
colors.

Vistalite  uses Cliff colors for portions of the landscape where the terrain
is  very steep.  The color Cliff 1 is used for slightly steep regions, Cliff
2  for  steeper portions and so on through the range of cliff colors.  Beach
color  is  used  for  the  boundary  (if  any) between the sea and the land.
Vistalite  uses Water colors for rivers and lakes.  Water colors 1 and 2 are
assigned  to  flat bodies of water.  Water colors 3 and 4 indicate rapids on
rivers.    Waterfalls are Water 5.  Horizon color is the color of the region
surrounding  the  Elevation Model Data.  This color need not be the color of
the  sea or of water at all.  Depending upon the effect desired, it might be
green to match the lowest landscape colors.

Sky  color  is  simply  the color of the sky.  You can obtain an interesting
effect  by making Sky and Horizon colors black and by setting the Haze value
to  0.  This creates landscapes that appear to be floating in space Sky Haze
is  the color that the sky fades to in the distance.  Haze is the color that
land  and water fade to in the distance.  Keep in mind that the thickness of
the  haze  (or magnitude of the haze effect) is set by the HazeDn setting on
the  Control  Panel.   You can produce another interesting effect by setting
Haze  and Sky Haze to black and the HazeDn value to a high number like 300.
This  makes  the  landscape look like a night scenelit by a light behind the
camera.

Exposure  and  contrast  are  set  with the Exposure and Contrast controls.
Higher  Exposure  settings  lead  to  brighter  pictures.    Higher Contrast
settings lead to more contrast in the images.  Only the R(ed) slider is used
to control Exposure and Contrast settings.

OK

The  OK  button  returns you to the main Control Panel using the changes you
have made in the Color Control Panel.

Spread

The  Spread  function provides for a smooth series of color changes from one
color  to  another.    To  use the Spread function click on the upper color,
click  on  Spread and then click on the lower color.  As an example, suppose
you want the lowest elevation of brush to be a dark green and the highest to
be  a  light  green.   You would set the Grass 1 color to a light green, the
Grass 4 color to a dark green and use Spread to fill in the colors for Grass
2 and Grass 3.

Quit

The  Quit button returns you to the Control Panel, resetting the colors back
to what they were before you opened the Color Control Panel.

Copy

The  Copy  button copies a color from one palette segment to another.  Click
on the color you want to copy, then click on Copy and, finally, click on the
color you want to change.  The second color is changed to be the same as the
first.

Swap

The  Swap  button  swaps two colors.  Click on one of the colors you want to
swap,  then  click  on the Swap button and, finally, click on the color with
which you want to swap.  The colors swap places.

Sound

Fractal music generated by Vistalite is a musical rendering of the values of
the polygons that Vistalite uses to generate the final image before display.
It is the sound of fractal mathematics in action

Colors

Sky
Sky  is  the  primary  color that Vistalite uses in generating the sky.  Sky
Haze alters this color when appropriate.

Cliff 1 - 4
Cliff  1  - 4 are the primary colors that Vistalite uses in generating cliff
regions in a landscape.  Cliff 4 is used for the steepest cliffs and Cliff 1
the  least  steep Vistalite uses shades of these colors when these areas are
in shadow.

Snow 1-4
Snow  1 - 4 are the primary colors that Vistalite uses in generating regions
of  the  landscape  that  are  above  the  snow line.  Snow 4 is the highest
elevation  above  the  snow  line  and Snow 1 is the lowest.  Vistalite uses
shades of these colors when these areas are in shadow.

Bare1-4
Bare  1 - 4 are the primary colors that Vistalite uses in generating regions
of  the landscape that lie between the tree line and the snow line, and that
are not as steep as cliffs.  Bare 4 is the highest such elevation and Bare 1
the  lowest.   Vistalite uses shades of these colors when these areas are in
shadow.

Tree 1-4
Tree  1  -  4 are the primary colors that Vistalite uses when drawing trees.
As  with  Snow, Tree 4 is used for trees at the highest elevation and Tree 1
for  the lowest.  Vistalite uses shades of these colors when these areas are
in shadow.

Beach
Beach is the primary color that Vistalite uses to separate the bottom of the
tree  area  from  any sea that has been generated.  Vistalite uses shades of
this color when these areas are in shadow.

Horizon
Horizon  is  the  primary color of the area that is at sea level surrounding
the topographic data.

Water 1-5
Water  1 - 5 are the primary colors that Vistalite uses for rivers and lakes
Water  5  is  used  for  the  fastest  water  and  Water  1 the most placid.
Vistalite uses shades of these colors when these areas are in shadow.

SkyHaze
Vistalite  adds  Sky  Haze color to the sky near the surface, depending upon
the amount of haze selected.  There is a smooth transition from Sky color to
Sky Haze color as the sky approaches the horizon in the distance.

Haze
Vistalite  adds  Haze  color  to land areas based upon the distance from the
camera and the amount of haze selected with the HazeDn value.

Grass 1-4
The  colors Grass 1 - 4 are used to draw the ground underneath trees whether
or not trees are enabled.  We find that brown or dark green shades look most
natural.  As with trees, Grass 1 is used at the lower elevations and Grass 4
at the higher elevations.

Bark 1-4
Bark  1  -  4  are  used  to draw tree trunks and larger branches.  They are
usually  set to dark brown but you might also select whites (Birch trees) or
other colors.

Exposure
Exposure  is  similar to the F-stop and shutter speed on a camera lens.  The
higher the exposure, the lighter the final image.

Contrast
Contrast regulates the contrast of the final image.  High contrast makes the
darker  areas  very  dark  and  the  lighter areas very light.  Low contrast
lessens the difference between the dark and light areas.

THE VISTALITE STATUS WINDOW

The  Status  Window  is  the area just below the topographic map.  Vistalite
uses  this  area to give you messages about what it is doing while rendering
It  also  indicates the mouse position while in the Camera or Target buttons
are selected.

The  following  sections  describe  the  messages  that are displayed in the
status Window.

X, Y, Z:

The X , Y , and Z values displayed in the status window while you are moving
the  mouse pointer over the landscape are the X, Y, and Z coordinates of the
landscape under the pointer.  If you think of north as the top of the screen
the  X coordinate represents the distance in meters east of the left edge of
the  topographic  map.    The Y coordinate represents the distance in meters
north  of  the  bottom  edge  of  the  topographic  map.    The Z coordinate
represents  the  elevation  above  sea  level in meters of that point on the
topographic map .

Generate

Vistalite is generating a new fractal landscape.

Color

Vistalite  is  calculating  the  colors  of  the polygons which comprise the
landscape  based  on  their  altitude  and  the  topography  of  the terrain
Vistalite  does coloring whenever you modify the snow fine, tree line or sea
level, or if you render an image at a smaller polygon size than before

Cliffs

Vistalite  is placing cliff colors on the steep areas.  Recalculating cliffs
takes  place  whenever  you  change  snow or tree lines, or if you render an
image at a smaller polygon size than before.

Shade

The  Shade  function  is  calculating  the amount of light reflected by each
polygon.  Vistalite recalculates shade when you draw a river or lake, select
a smaller polygon size or vary the light position.

Tree

During  the  Tree  function,  Vistalite calculates the location of trees and
grass for inclusion during the Render function.

Sky

During  the  Sky  function, Vistalite is drawing the sky, including sky haze
effects.    This  may  take several seconds and Vistalite does not display a
counter.

Horizon

During the Horizon function, Vistalite draws the ground, ocean or space that
surrounds  the  DEM  portion  of the view.  Because of the haze effect, this
requires several seconds.

Render

Vistalite  is drawing DEM polygons.  The image cannot be seen as it is being
drawn,  unless  you  select Show Render from the GrModes menu, because it is
drawn to a virtual screen.  We designed Vistalite in this manner to increase
its  rendering  speed and the flexibility of its output.  The virtual screen
format  makes drawing polygons very fast, especially since the final display
may  be  in  any  of the Amiga's display modes.  In the final step Vistalite
converts  the  image  from the virtual screen to display on the real screen.
The image is transferred to the Amiga's screen in several bands from the top
to the bottom of the screen.  Vistalite draws the virtual image with 15 bits
of  color  information  (32,768 colors).  Vistalite does its best to convert
the  32,768  possible  colors in the Virtual screen to the limited number of
colors on the real screen.

In  HAM  mode  Vistalite  uses two different algorithms for drawing the real
screen.  If the polygon size is set to either 4 or 8, Vistalite uses a crude
but  fast  algorithm.   If the polygon size is set to 1 or 2, it uses a more
precise  but  slower  method.   Pixel dithering can be used in HAM 8 mode to
increase the number of colors possible to a full 256K.

Vistalite  calculates  steps  like coloring and shading only to the level of
detail  required  for the current polygon size.  Vistalite saves the results
of  these  calculations  in  memory, so that it will not have to recalculate
them later The program does not recalculate these tables when switching from
a  small  polygon  size to a larger polygon size.  It uses the data from the
small  polygons  to draw the larger polygons.  Therefore, Vistalite does not
have to recalculate tables if you re-select the smaller size polygons.  Once
Vistalite has made the calculations for small polygons, it will not color or
shade  renderings  with  large  polygons  exactly  right.   However, this is
preferable  to recalculation because it saves time.  Large polygon sizes are
usually  used for previewing, so it doesn't matter if the image generated is
not  precise.    You can force Vistalite to recalculate the color tables for
large  polygons  by  changing the tree line or snow line.  Even entering the
same  value again forces recalculation.  To force reshading, change or reset
any of the lighting values.

VIEWER

Viewer  is  a  proprietary animation player written by Hypercube Engineering
and distributed by Virtual Reality Laboratories, Inc.  It allows you to play
VANIM  files  at  up  to 13 frames per second from your hard disk.  It has a
very simple straight forward interface and is quite easy to use.

To  use  Viewer,  simply type Viewer.  Select the animation you wish to view
from Viewer's Load menu.

You can control the speed with which Viewer plays your animation by pressing
the  nunmber  keys  on  your main keyboard.  (Not the numeric keypad!!!) The
number  1 is slowest and the number 0 is fastest.  The numbers between 1 and
0 represent increments of speed change.

You  can use the numeric keypad to control the direction that your animation
plays,  as  well as single frame, skip ten frames, go to beginning and go to
end.

1  Go Back 1 Frame
2  Reverse
3  Go Forward 1 Frame
4  Go Back 10 Frames
5  Stop
6  Go Forward 10 Frames
7  Go To First Frame
8  Forward
9  Go To Last Frame

Exit from the Viewer program by pressing the ESC key.

When viewing a large anination, it helps to have a lot of disk buffers.  Use
the AmigaDOS AddBuffers command to add disk buffers.  We recommend about two
buffers  for  each  frame  of the animation.  For example, a 500 frame VANIM
file  (24  megabytes in HAM, no interlace or overscan), on drive DH0: should
have  about  1,000  disk  buffers.    This  can  be  accomplished  by typing
AddBuffers  DHO: 100O at the AmigaDOS Shell or CLI prompt.  You only need to
do  this once each time you re-boot your Amiga.  A thousand buffers consumes
about half a megabyte of memory.

APPENDIX A
----------

What are Fractals and Fractal Geometry?

by Daniel Wolf Ph.D.
(Author and Publisher of Fractal Pro, President of MegageM.)

The  concept  of  fractal  geometry  is the basis of Vistalite's capacity to
generate imaginary scenes.  Many computer graphics enthusiasts, espec cially
in the Amiga community have become interested in fractal graphics Mandelbrot
and  scenery  programs.    The popularity of fractal graphics using personal
computers traces back to the appearance of stunning images of the Mandelbrot
Set  (a  type of fractal object) on the cover of Scienfic American in August
of  1985.    That  widespread  exposure of these strangly beautiful abstract
objects  led  many  amateur  and  professional  program mers to the original
source  book  on  fractals:  The  Fractal  Geometry  of  Nature  by   Benoit
Mandelbrot.   While fractals and fractal geometry have become hot buzz words
in  the  computer  graphics  field, it is not exactly obvious what they are.
The following description is simplified, and interested students and readers
should read Mandelbrot's book on the subject.

We  owe  the  word fractal to Mr.  Mandelbrot, a mathematician and Fellow at
IBM's  Watson  research organization in New York.  Fractal refers to objects
with  fractional  dimensions.   That is, objects which don't really fit into
the  ordinary  world  of  things like lines (one dimensional), surfaces (two
dimensional) and solids (three dimensional).  Fractals are objects which fit
in between these normal dimensional objects.  Mandelbrot took an interest in
a  long-neglected  area  of mathematics which originated at the turn of this
century.   Some devotees of geometry at that time began to study lines which
didn't behave like ordinary lines

If  you  read  Mandelbrot's  book  you'll  become  familiar with some of the
mathematical  history  of things like Peano curves, Hilbert curves, and Koch
snowflakes.  What makes these objects so strange, and what led Mandelbrot to
look  deeper,  are  two  properties:  these  "lines"  tend  to fill up a two
dimensional  surface  (they  act  as if they are something between lines and
planes)  and  their appearance seems to be identical no matter how much they
are magnified.  Magnified small portions of these fractal lines tend to look
like the whole unmagnified line.  Odd indeed!  Mathematicians at the turn of
the  century tended to call such obbjects pathological and didnt have a good
way  of integrating them into the rest of mathematics, especially geometry.
Geometry  was  mostly  dominated by the study of well behaved smooth, lines,
planes  and  solids.    Mandelbrot  made  a  systematic study of these weird
fractional  dimension  geometric  forms  and  helped  bring  them  into  the
mathematical  fold.   Mandelbrot also showed how these objects are models of
many  things  found in the natural world, like surface textures of mountans,
coastlines  of islands and branching designs of plants, trees, blood vessels
and lung tubes (bronchi).

If  you  want a mental picture of how Vistalite exploits fractal geometry to
generate  natural  looking  land surface textures, take the following mental
journey into the process of crumpling a sheet of paper:

1. Imagine a flat triangular sheet of paper.

2. Divide the sheet into a small number of sub-triangles.

3. Randomly  select some  of the intersection points and raise or lower them
   (by a large amount) above the original plane of the flat sheet

4. Now divide the sub-triangles into smaller sub-triangles.

5. Randomly  raise and lower some of  the newly  created corner  points like
   you did in step 3, but by a smaller amount than in step 3.

6. Keep  repeating steps  4 and 5, making smaller and smaller sub-triangles,
   and  raising  and  lowering corner points randomly by smaller and smaller
   amounts at each step.

7. Stop  when  you've  reached  a  point  where  each smaller division  into
   sub-triangles  can't  make any more difference in appearance on a limited
   resolution display like a computer monitor.

8. Now  color  all  the  little  sub triangles by  a method which makes  the
   highest corner points white (snow on the mountain tops), lower ones brown
   and green (mountain sides with trees) and the lowest ones blue (a lake at
   the bottom of the mountain valley) .

If  we  perform  steps 4 and 5 using some regular (non random) technique, in
the  end  the highly crumpled surface would be a lot like the first fractals
explored  by  Mandelbrot;  they  would  look  similar at any degree of magni
fication  at  which  they are viewed.  The introduction of randomness to the
process  makes  them  look  similarly  random  at different degrees of magni
fication.

If  you  are interested in further exploring fractal geometry, here are some
great books:

The  Fractal  Geometry of Nature (by B.  Mandelbrot), The Beauty of Fractals
(by  H.    Peitgen and P.  Richter) and The Science of Fractal Images (by H.
Peitgen and D.  Saupe).

APPENDIX B
----------

The Landscapes

Most  of  the  landscape  DEM  files were obtained from the U.S.  Geological
Survey  (USGS) and are accurate to within 30 meters.  Some of the files were
assembled  to fit into Vistalite and therefore may not be perfect where they
are  joined.    The following is a partial listing of the DEMs included with
your Vistalite package.

ElCap.dem:

ElCap  is  a  section  of Yosemite Valley in Califomia out of which rises El
Capitan,  a  very  large  (about  1000  meters)  granite  cliff formation at
coordinate 2520,5 760 (X, Y) in the DEM data.  This landscape was created by
joining  together  two  USG5  DEM files and then clipping out the section of
interest.   A small "scar" that runs North/South where the USGS data did not
quite  line up can be seen.  The joining scar is most apparent in the Valley
with the sun shining from the east or west at approximately 3400,4980.  This
DEM file is as accurate as the original USGS data

HalfDome.dem:

The  HalfDome  section  of  Yosemite  Vallev  contains  the   famous granite
formation  know  as  HalfDome at location 5100,7260.  The method used by the
USGS  to digitize the terrain led to some distortion at the top and edges of
Half Dome.  The jaggy bump at the top of Half Dome is a USGS artifact.  This
DEM  file  is  as  accurate  as  the  original USGS data since it was simply
clipped out of a DEM file.

CraterLake.dem:

Crater  Lake  is  the caldera of an ancient volcano in Oregon.  The walls of
the  caldera  rise  approximately 1250 meters from the bottom of the lake to
the  top  of  the caldera.  The DEM data includes the underwater elevations.
The  lake  fills  the  caldera  to a level about half way up the walls.  The
mound  near  the west edge of the caldera is Wizard lsland.  It is separated
from  the  edge by the lake.  The circular mound near the top of the caldera
is  completely  submerged.  The lake can be filled with water using the Lake
function  of Vistalite.  Clicking the mouse button about halfway from Wizard
Island to the edge of the caldera gives approximately the right water level.
In  Order  to  inciude  the entire lake in the file, everything was adjusted
down by a factor of 0.6.  Therefore, to convert elevations or distances into
actual meters, take the values given by Vistalite and divide them by 0.6.

MSHB.dem: and MSHA.dem:

Mt  St.    Helens  is the volcano in Washington that blew its top on May 18,
1980.  The explosive eruption was preceded by amounts of intense earth quake
activity.    A  150  meter  bulge started to grow in April at a rate of five
meters  per day.  A magnitude 5.1 earthquake set into motion the collapse of
the bulge and the following explosion.  Winds from the blast were calculated
at  670  miles  per hour.  Almost everything within eight miles of the blast
was  obliterated.    Virtually  all  trees were flattened at distances up to
nineteen  miles  from the volcano.  Significant amounts of volcanic ash fell
as far as one thousand miles away.  The new crater is about three kilometers
wide  and  700  meters  deep.    The "before" data was generated from stereo
photographs  taken  in  1979.  The "after" data comes from photographs taken
late in 1980.

Julia.dem: and Mandelbrot.dem:

Julia  and  Mandelbrot landscapes are artificially generated by a mathematic
cal  algorithm.   You may have seen Julia sets and Mandelbrot sets displayed
as  colors on a two dimensional screen.  If you have a Mandelbrot generation
program  that  handles  Julia  sets,  or  a  Julia  generation  program, the
locations  are  as  follows:  The  Mandelbrot  is   1.255525   real 0.381060
imaginary, with a diameter of approximately 0.007; the location of the Julia
set is 0.75 real -0.11 imaginary, relative to the Mandelbrot set.

Vantage.dem:

This  is  a  portion  of  the Columbia River in the state of Washington that
forms the north portion of Wanapum Lake.  It is located in Ginkgo State Park
near Vantage, Washington.

Arrowhead.dem:

This  is  the  Lake  Arrowhead  region  of  the  San Bernardino Mountains in
Southern  California.   The low lying region forms a lake in the shape of an
arrowhead,  hence  its  name.   The lake was formed by the addition of a man
made dam, which is not part of the DEM data, so it is impossible to fill the
lake  without  flooding  the landscape below.  This is clipped from a larger
data  set  that  is  also  available  from  VRLI, calied "Lake Arrowhead and
Environs."

SanGorgonio.dem:

This is south of the Big Bear Lake region of the San Bernardino Mountains in
Southern  Califomia.  It contains Mt.  San Gorgohio, a 3500 meter peak in an
area  known as the San Gabriel Wilderness.  It is clipped from a larger data
set, available from VRLI, called the "San Gorgonio Mountain and Environs."

BigSur.dem:

This  is  the Big Sur area along the coast of north central California, just
south  of  the  Monterey  Peninsula.   It contains Pfeiffer Big Sur National
Park.    It  is  one  of  the more beautiful camping areas in California and
contains  one  of the southernmost groves of redwoods.  It is clipped from a
larger data set, available from VRLl, called "Big Sur and Environs."

MtBaldy.dem:

Contrary  to  popular  belief  there  is  no  such mountain as Mt.  Baldy in
southern  California.  That is the name of the village on the slopes of Mt.
San  Antonio.    This  DEM  is located in the San Gabriel mountains south of
Wrightwood.    This  has been clipped from a larger data set, available from
VRLI, called "Mt.  Baldy and Environs."

MtAdams.dem:

This  contains  Mt.  Adams, in the southern portion of Washington state.  It
is  part  of  the  Mt.  Adams Wilderness and is a good example of a volcano,
reaching from a height of over 3700 meters at its peak.  It was clipped from
a larger data set, available from VRLI, called "Mt.  Adams and Environs".

APPENDIX C
----------

Glossary of Terms

AI.
Artificial  Intelligence.    The  ability of a program to incorporate expert
judgement enabling it to imitate intelligent decision making.

Aliasing Artifacts
Objects which appear in a landscape which are not derived from mapping data.
They may reside in the data or they may be foiled as a result of the program

Caldera
The crater at the top of a volcano.

Deluxe Paint
A paint program published by Electronic Arts.

DEM
A  Digital Elevation Model or DEM is a model of a landscape reduced to three
dimensional digital coordinates.

Digi Paint
A  paint  program  published  by  NewTek  and  used to display or modify IFF
picture files created by Vistalite.

Digital Elevation Model
A  Digital Elevation model or DEM is a model of a landscape reduced to three
dimensional digital coordinates.  It is commonly abbreviated as DEM

Dithering

Dithering  is a program function which blurs the boundaries between polygons
in order to more closely simulate realism in landscape creation.

Pixel  dithering  is  a  tecimique  used  at  the  pixel level to create the
illusion  of  more  colors  than can actually be displayed.  This is done by
intermixing or dithering pixels of different colors.

Fat Polys
Foreground polygons which are relatively larger than the polygons in distant
scenes  are  called  Fat Polys.  Fat Polys are a function of perspective and
the accuracy of the data being rendered.

Fractal
Fractiornal  dimension.    Most  math deals with whole numbered dimen sions.
One  dimension  is  a line.  Two dimensions are a surface.  Three dimensions
are  a  solid.   Four dimensions are a space time solid and so on.  Fractals
deal  with  non-whole numbered dimensions and fractal geometry is capable of
producing  pictures  which  are  remarkably  similar to natural phenenomena,
particularly geological shapes

Fractal Pro
A professional level fractal program published by MegageM.

HAM
Hold and modify, or HAM, is an Amiga display mode used to all 4096 colors in
the Amiga color palette.

Haze
Haze  is  the atmospheric occlusion that increases with the distance between
the eye and the target.

IFF
IFF is the standard graphic file format used on the Amiga.

Jaggies
Partial  polygons  which  produce  jagged lines often at the ridge line of a
landscape and sometimes in the foreground.  Jaggies distort the realism of a
scene

Olympus Mons
A  volcano on Mars.  Olympus Mons is an extremely vast feature.  The base of
the  volcano  covers  an area the size of Nebraska.  Olympus Mons also has a
feature which is unique within the solar system.  The base of the volcano is
well  within  the  thin  atmosphere  of  Mars.    The peak of the volcano is
virtually above the Martian atmosphere, allowing launch to orbit by magnetic
acceleration.   A tramway could be constructed from the base of Mons Olympus
to  the  top  of Mons Olympus.  Liquified carbon dioxide water, hydrogen and
oxygen  (condensed  from  the  atmosphere)  could  then  be  transported for
magnetic  rail  launch  into orbit at the top.  A return from space could be
accompiished  with  aero-braking.  Therefore, Mons Olym pus could become the
basis  for  a  Martian  space  transportation system which would not require
rockets.

Polygons
The  basic  geometric  units  with  which  Vistalite  renders landscapes.  A
polygon is a two dimensional shape having at least three linear sides.

Ray Tracing
A  method  of  image  generation  in  which  a  hypothetical ray of light is
projected,  reflecting  off  the  target  and  ultimately colliding with the
camera.

Topography
The science of drawing maps representing the surface features of a region

Topology
The study of shapes.

UsGs
United  States  Geological  Survey.  The, USGS has created three dimensional
maps  of  much of the United States, some undersea landscapes and some extra
terrestrial  landscapes.    Much  of  the work done by USGS is in the public
domain and can be adapted for use with Vistalite.