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Almathera Ten Pack 4: Demo 1
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genesis
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about_genesis
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Text File
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1995-03-16
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7KB
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144 lines
ABOUT GENESIS
GENESIS is an uniquely flexible and powerful program for
generating and rendering fractal landscapes. Original algorithms
allow incorporating fractal rivers as integral parts of the landscapes,
with natural looking river valleys, gulleys, waterfalls, and lakes.
A number of parameters can be varied to modify the landscape
construction process and change the character of the final landscape,
and there is also great flexibility in the rendering. Vary the
observer position, view direction, camera field of view, sun direction
and elevation angle, sea level, textures and colors of the different
landscape elements, and choose between solid-shaded or wireframe draw
modes, and between faceted shading or three versions of smooth shading.
While conventional Gouraud shading is one of these options, it is far
surpassed in quality by the Best custom shading option, which preserves
the small bumps and gullies in the landscape while making the triangle
edges invisible and allowing much more subtle treatment of contour
boundaries. The sun casts true shadows, which adds greatly to the drama of
scenes where the shadow of a mountain is projected far out onto
a "lake" or the "sea".
Every effort has been made to keep the program easy to use --
all the parameters have default values, and the observer can be
positioned using a simple and intuitive graphical interface.
The author of GENESIS is Professor of Physics at the
University of Washington in Seattle. His work with fractal landscapes
has led to invitations from Benoit Mandelbrot to speak at IBM and Yale.
Features of the complete version of GENESIS are listed below. Features
omitted from or only partially implemented in this Demo version are
enclosed in square brackets.
1. Control over fractal properties, such as
the fractal dimension of the landscape,
how roughness varies with height,
the density of springs and the fractal properties of the river
networks,
the fractal dimension of the rivers (i.e., the amount of meandering),
the nature of the river valleys, narrow or broad.
Vary the fractal properties at each stage of subdivision
of the landscape, it you wish.
[Choose from over 1 billion random seeds.]
2. The option of customizing the heights of individual points
at an early stage of subdivision, using a simple graphical
interface.
3. Landscapes of incredible complexity, with up to 118000 points,
236000 triangles, 1200 permanent springs, 2500 lakes, comparable
in some respects to what can be done on advanced graphics
workstations and mainframes.
4. Random fractal rivers which co-evolve with the landscape, greatly
increasing the realistic feel and graphic interest of the
landscapes. The rivers displayed when the landscape is rendered
originate in springs or "lakes". They have an adjustable depth,
and a corresponding width, which increases downstream. The steeper
parts of the rivers can be displayed as "rapids" or "waterfalls".
5. An adjustable sealevel. Smoothly interpolated shorelines for the
sea and the lakes. [Optional extension of the sea (or a ground plane
with the color of the lowest contour) beyond the edge of the
landscape to the "horizon".]
6. Illumination by a "sun" which can be in one of 6 horizontal
directions, at any angle from the horizontal, and casts shadows.
7. [Arbitrary placement of the observer anywhere in 3-dimensional space
around the landscape, with an arbitrary view direction. The "camera"
has an adustable focal length.]
8. Three solid-modelled draw modes of various screen resolutions, and
two wireframe modes. The land is colored according to height and
steepness, with up to 3 contour levels for solid draw modes and up
to 6 in wireframe. The solid triangles are shaded in brightness
according to the angle they make with the sun. The range of
brightness in the sun and the contrast with the shadows can be
either "high" or "low". Triangles steeper than a certain "maximum
slope angle", adjustable separately for each contour, are colored
as "cliffs". Contours can be "blended", in that the contour to which
a triangle belongs can depend on the steepness of the triangle as
well as its height. Furthermore, there is a choice between a "smooth"
and "bumpy" texture for the triangles of each landscape element,
corresponding to different types of dithering. The basic color of each
contour, the cliffs, etc., can be freely chosen.
9. Optional smooth shading of each contour separately, using either
Gouraud shading or custom shading methods which preserve the fine
detail in the landscape much better than Gouraud shading. Optional
dithered transitions from sun to shadow and from one contour to the
next. [The amount of contour dithering and its sensitivity to
local curvature of the landscape surface can be adjusted over a wide
range.]
10. Various degrees of overscan, up to full video overscan.
11. The pictures are normally 32 colors in low-res and 16 colors in
high-res, but dithering is used to simulate many intermediate
shades between the pure colors of the Amiga palette. If desired,
low-res pictures can be converted to Hold-and-Modify (HAM) display
mode. [Pictures can be saved as standard IFF files.]
12. [Automatic support for the Photon Video Transport Controller
software, which allows directly recording pictures frame-by-frame
onto videotape. Requires a single-frame VTR and other additional
hardware.]
13. [Height and other data necessary to reconstruct a landscape
can be stored to disk.]
14. [Script commands for drawing a whole series of pictures of
a given landscape in "batch" mode, with varying observer position,
sun angle, etc., which is particularly convenient for creating
animations. Scripts can be created automatically as you use the
menus and requesters to set up each picture, or alternatively can
be written and/or modified with a text editor.]
15. [An ARexx interface, allowing external ARexx macros to control
almost all functions in GENESIS, including some special operations
only available through ARexx. The interprocess communications
facilitated by ARexx make it possible to completely automate the
construction of an animation. Control the path of the observer
and transfer pictures from GENESIS to other programs for special
processing or compression into Anim format.]
16. [Special ARexx commands to modify landscapes, trace out rivers,
and analyze the fractal properties of rivers and landscapes.]
17. [Creation of object files for 3-D modelling and animation
programs, allowing entire landscapes or arbitrary rectangular
"cut-out" portions of landscapes to be imported directly into
Turbo Silver 3.0, Sculpt 3-D, Sculpt-Animate 4-D, and
Videoscape 3D 2.0.]
This demo version of GENESIS is copyright © 1990 by James M.
Bardeen, but may be distributed freely as long as this file and the
Genesis_Docs file are included with the program. It may not be used
for any commercial purpose without permission from the author or
Microillusions, and may not be altered in any way.
For more information, or to order release 1.0 of GENESIS,
write to Microillusions, P.O. Box 3475, Granada Hills, CA 91394,
or call (818) 785-7345.