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 rwed where 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 .dem rwed at the CLI or SHELL prompt, replacing 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.