_____________________________ Chapter 4 Vistapro User Manual _____________________________ CONTROL PANELS The Vistapro Control Panels are split into three main sections, which we call the Upper, Middle and Lower Control Panels. In addition, there is a Color Control Panel. The map in the window represents the landscape area you loaded into Vistapro. The small black + symbol on the map is the Target. The small black box symbol is the Camera. UPPER CONTROL PANEL ------------------- The target represents the point at which you are aiming the camera. Its location is measured in meters from the lower left hand corner of the topographic map and in meters above sea level. After selecting the Target button on the Control Panel, you can place the mouse pointer anywhere over the landscape and click the left mouse button, setting a new target position in the X and Y direction. The Z, or height value, is set to the elevation of the landscape at that X-Y coordinate. That is, the Z value in the target represents the actual elevation of the landscape at that point. As an alternative, you can place the target precisely by entering locations directly into the X, Y and Z numerical gadgets. To change a value, select the appropriate numerical gadget by clicking the left mouse button in the numerical gadget. Use normal editing techniques to change the values. (Backspace, delete, etc.) You may also delete the entire contents of the gadget by pressing the SPACE bar. This works in all the numerical gadgets in Vistapro. When finished editing press the ENTER key or the left mouse button to accept the new value. Press the ESCAPE key or the right mouse button to stop editing and restore the original value. 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 hand 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 on the topographic map, and the Z coordinate is in meters above sea level. Select Camera on the Control Panel. By placing the pointer anywhere over the landscape and clicking the left mouse button, you can select a new camera position in the X and Y direction, and the Z or height value changes with the elevation of the landscape. The Z value of the camera is set to 30 meters above the landscape. Alternatively, one can place the camera precisely by entering locations directly into the X, Y and Z numerical gadgets. To change a value, select the appropriate numerical gadget by clicking the left mouse button inside the gadget. Use normal editing techniques to change the gadget values (backspace, delete, etc.). Delete the entire contents of the gadget by pressing the SPACE bar. This works in all the numerical gadgets in Vistapro. When finished editing press the ENTER key or the left mouse button to accept the new value. Press the ESCAPE key or the right mouse button to stop editing and restore the original value. 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. You can use the locks when you want to restrain 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, you could 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 the same. 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 numerical 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. Vistapro will restrain both the camera and target X, Y, and Z values as long as the locks are depressed. 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 one might do when taking a photograph. When you type in a new distance value Vistapro will change the camera's X, Y, and Z coordinates to match the desired distance as well as it can. The Bank, Heading, and Pitch values will not change. dX dX displays the difference between camera and target X dimension values. The user 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 dimension values. The user 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 dimension values. The user 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 to explain axes. Bank ---- Bank controls the rotational angle of the camera around its longitudinal axis. Imagine an airplane. You can describe the longitudinal axis as an invisible line drawn from the tail of the airplane to the nose. Any 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 would cause rotation in a clockwise fashion as viewed from the tail. The left wing would raise and the right wing would lower. Note that when the camera rotates clockwise the view that is rendered will appear to have rotated in the opposite direction. Head ---- Heading describes the rotational angle of the camera around its Z axis relative to the landscape. Imagine an airplane . You can describe the Z axis as a line drawn from the top of the airplane to its bottom. Any rotation around this axis causes the airplane to turn right or left. A positive rotation causes the airplane to turn right. Pitch ----- Pitch is the rotational angle of the camera around its wing axis. Once again, imagine an airplane. A line drawn through the wings from the left side of the airplane to the right side describes the pitch axis. Any rotation around this axis causes the airplane to move the nose either up or down, with a positive rotation causing the nose to go up. MIDDLE CONTROL PANEL -------------------- Sea --- 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 1000 meters as sea level, all points below 1000 meters will sink to 0, 2000 meters will sink down to 1000 meters, 3000 meters will sink to 2000 meters, etc.Vistapro will erase rivers and lakes (if present) when it generates a new sea level. Vistapro will need to color and shade the landscape again.Vistapro has a button for selecting sea level. You click on the Sea button and then select the level by clicking on the topographic map. You can specify the Sea level explicitly by typing the value into the numerical gadget immediately below the Sea button (See also Waves). Tree ---- You can use the Tree level button 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. Vistapro's AI (Artificial Intelligence) rules will 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 into 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 the DrwTre (draw tree) button is not selected Vistapro will not actually draw the trees, it will just use the tree colors to color the ground.You can use the Tree button to select the tree level. Depress the Tree button and then click on the topographic map at a location which has the desired altitude. You may also numerically specify a tree level by typing a value into the numerical gadget located below the Tree button. Snow ---- The Snow level is the lowest elevation where Vistapro will cover the landscape with snow. The AI rules in Vistapro use this value to calculate where to use the snow colors. Vistapro will compensate 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 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 gray 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 Snow button to select the snow level. Depress the Snow button and then click on the topographic map at a location which has the desired altitude. You may also numerically specify a snow line by typing a value into the numerical gadget located below the Snow button. Haze ---- In the real world, the farther away an object is, the more it is occluded by the atmosphere. The haze function in Vistapro simulates this effect, adding to the three-dimensional feel of the resulting image. You can specify how thick the haze is by changing the Haze value in Vistapro. (You can also change the color of the haze-- see chapter 6, Color Control Panel.) You enter the Haze value by entering a number in the numerical gadget below the Haze button. * A value of 0 will completely eliminate the haze effect * Small values (below 100) will give very little haze * Medium values (100-1000) will give medium haze * High values (over 1000) will create very thick fog. You can also "automatically" calculate the haze value by pressing the Haze button. Vistapro 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 ---- The lake function adds lakes to a landscape. Select Lake on the Control Panel. Then, using the mouse, place the pointer on the landscape at the lake level desired, and click the left mouse button. Example: If one places the pointer in a shallow valley at 2100 meters, water will begin to fill the valley until it reaches the 2100 meter mark, as it would in nature. If there is any portion along the edge of the valley that is below the 2100 meter mark, 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 uncertain about landscape heights, move the mouse pointer around any suspect areas watching the Z value on the status line. Then find the lowest point in the pass to determine the maximum safe altitude for creating the lake. Lake generation can be aborted by pressing the ESCAPE key or the right mouse button while the lake is being generated. To create a lake, press the Lake button and then click on a starting point on the topographic map. You will see the lake being created on the topographic map in black. Once the lake has been completed the black lake will be redrawn in blue. River ----- Vistapro's River function creates rivers which flow downhill from the selected starting point. If a river reaches a depression it will slowly fill it (creating a pond or lake) until the lake overflows. The river will continue flowing down hill until it reaches the ocean or the edge of the topographic map. You may stop the flow of a river by pressing the ESCAPE key or the right mouse button. Although you can always fill a lake using the River function and wait until the lake fills up, 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 will be 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 originally a river or lake) 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. Of course, if you want the main river to significantly widen, start a new river on top of the old one as many times as you like. It will grow wider with each iteration.You generally will want to start rivers at the head of a valley, but it is possible to start a river anywhere on the topographic map. Smooth ------ The Smoothing function smooths or erodes the landscape, removing the harsher, more jagged edges of hills and mountains. Smoothing often improves the appearance of landscapes, and it is especially useful when dealing with fractal landscapes. You should use the smoothing function sparingly with DEM files if data integrity is important, as it distorts data. Pressing the Smooth button on the Control Panel will invoke the smoothing function. This is a repeatable, refining function, meaning that it can be run over and over again, smoothing (eroding) the landscape more on each pass. Smoothing is also used to obtain snow covered peaks. Because of the design rules of the AI algorithms, and as is also true in nature, it is very rare that the summits or peaks of mountains are completely snow covered. It is more often the case that due to the steep nature of the cliff faces and other contributing aspects, such as wind and snow weight, snow does not cover the peaks of most mountains. However, since it may be desirable artistically to create a completely snow-covered mountain, smoothing the mountains will often give this effect. Enlarge ------- The enlarge function allows you to select a portion of the landscape and enlarge it to fill the entire topographic area. The intermediate data points are either filled with the average of the points around them or filled with duplicates of the nearest point . To invoke this function press the Enlarge button. You will then see a box that follows the mouse cursor around the screen. Place the box over the section that you want to enlarge and press the left mouse button. Vistapro will open a requestor near the top of the screen asking you to select either the Interpolate (average) or Duplicate mode. Select the desired mode and the area inside the box will be enlarged to fit the entire topographic area. Any rivers, lakes, or oceans will be lost. The differences between the two modes is best described by a diagram. Consider the side of a small hill viewed from a cross- section; in Interpolate mode, the hill will double in size in all dimensions and the side of the hill will remain smooth; in Duplicate mode the hill will also double in size, but it will become stepped: Original data: \ \____ Interpolate mode: ____ \ \ \ \___ "in between" data is the average of the points around it. Duplicate mode: ÄÄÄ¿ ³ ÀÄÄ¿ ³ ÀÄÄÄ "in between" data is the same as the points near it. Waves ----- Vistapro can generate waves on the sea. To enable this feature, select Waves from the main control panel before creating the sea. To deselect the waves feature, re-select the Waves button. When you enable waves, Vistapro will generate them along with any new sea that is generated. You can add waves to an already generated sea by selecting the Waves function and setting a new sea level, or the same sea level (value 0). While Vistapro is generating waves, it displays a message on the status line. Vistapro generates waves (if specified) only when a new sea level is set, both on fractal and real-world landscapes. DrwTre ------ Vistapro has two types of trees that it can draw while rendering. Vistapro draws the trees only if the DrwTre (Draw Tree) button is depressed. When you press the button a requestor will appear at the top left corner of the screen. From it you specify the size and type of trees to draw. The size is specified by the numerical gadget at the center of the requestor. You must select the size before the type since pressing either of the type buttons will close the requestor. Good sizes range from 20 to 80 meters. Very small trees may appear too sparse; very large trees will be distorted or overwritten by subsequent polygons of the landscape. After selecting the tree size (or accepting the default) select the type by pressing either the Pine or Oak button. Pine trees will have roughly triangular shapes like a Christmas tree. Oak trees will have roughly round shapes. Trees may be drawn anywhere that TREE1 through TREE4 (see CMap section) colors are used. In addition the number of trees drawn is affected by the TreDns (Tree Density) setting.Trees are drawn using TREE1 through TREE4 colors, plus a small randomizer so that they are not all the same color. You cannot select the brown shades Vistapro will use for the tree trunks. The ground underneath trees is drawn as a slightly darker shades of BARE1 through BARE4. Trees can take a very long time to draw. Depending on how many trees are drawn, trees may take more than twice as long to render as the same scene without any trees for Vistapro to draw. LckPal ------ Vistapro renders pictures using the PC's 256 color modes. Vistapro calculates the best 256 colors to use just before rendering each image. The colors it picks are based on the colors in the landscape, the current Contrast and Exposure settings, and the Haze colors and value. Calculating a new 256 color palette can be time consuming (about 40 seconds on a 20 MHz 386) so we have given you the ability to lock the color palette. When the palette is locked Vistapro will continue to use the last palette generated. All succeeding images will be drawn with that palette until the color palette is unlocked. Locking the palette is especially useful when previewing an image, playing with the haze settings or the Color Map. When you are ready to render the final image, unlock the palette so that Vistapro will generate the best possible palette for that image. The palette is locked when the LckPal button is depressed. It is unlocked when the button is up. CMap ---- You can select the CMap button to display and activate the Color Control Panel. See Color Control Panel for more information. Poly ---- Vistapro produces 131,072 polygons at its finest resolution. The Polygon Size function controls the relative coarseness of the landscape image. A size of 8 generates 1/64th as many polygons (1/8th on each axis) as a size of 1, and they are 64 (8 x 8) times as large. That is, a landscape can consist of 131,072 size 1 polygons, 32,768 size 2 polygons, 8192 size 4 polygons, or 2048 size 8 polygons. You can use the larger polygons to generate quick previews of landscapes. When you are happy with your camera and target placement, use smaller polygons. The smaller the polygons, the longer it takes to generate the image. The larger the polygon size number, the less detail that will show up in the image, because Vistapro is displaying only a fraction of the original data. The lower resolutions (higher poly number, i.e. 4, 8) are useful for quick test renderings to check for landscape color, light placement, proper framing and exposure settings. TreDns ------ TreDns (Tree Density) controls how many of the polygons assigned TREE1 through TREE4 colors will also have trees drawn on them. Useful values range from 0 to 300 with low values giving low tree densities, high values giving high densities. Values below 0 are treated the same as 0, values above 300 are treated the same as 300. A value of 150 will result in one half of the TREE colored polygons having trees rendered. To change the Tree Density value, click on the numerical gadget immediately below the TreDns label and type in a new value. Press ENTER when finished. Dither ------ Vistapro generally colors landscapes by altitude. The lowest altitudes are colored with TREE1 through TREE4 colors, middle altitudes are colored with BARE1 through BARE4 colors, and the highest altitudes are colored with SNOW1 through SNOW4 colors. Each of the 130,000 triangles that make up the landscape is assigned a color, based on its altitude and several other factors. The Dither value sets the fuzziness of the division between color bands in Vistapro. A setting of 0 will give the tree-line and snow-line very sharp boundaries. The default setting of 200 gives a moderate amount of dithering of the colors. A large value like 1000 will make 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 numerical gadget on the Main Control Panel. Change the number from the keyboard and press ENTER. Useful values range from 0 to 1000. VScale ------ Vistapro allows you to vertically re-scale any landscape. Typing a number into the Scale numerical gadget will cause Vistapro to scale the landscape as requested. For example, if you type in 2.0, Vistapro will stretch the landscape out vertically so that mountains are twice as tall, etc. Values between 0.0 and 1.0 will cause Vistapro to flatten the landscape. Values below 0 cause the landscape to flip over (valleys become ridges, mountains become pits) before Vistapro scales them. The number typed in always results in a landscape which is that value times the original landscape. The user can save landscapes after scaling. You can generate some interesting effects with the scaling function. You can flip landscapes upside down by using negative values. Scaling mountains so that the top will exceed 32000 meters and then scaling it back down to normal will result in mountains with big pits or calderas. Scaling to very large values can even cause several layers of this effect. The result shows a mountain inside a collapsed mountain inside a collapsed mountain. Scaling mountains down until they are very small and scaling them back up will result in stepped mountains. Main ---- The Main button enables and displays the Main Lower Control Panel. See Main Lower Control Panel for details. Lens ---- The Lens button enables and displays the Lens Lower Control Panel. You can use this to select the type of lens the Camera is using. See Lens Lower Control Panel for details. Frac ---- The Frac button enables and displays the Fractal Lower Control Panel. You should use this when generating random fractal landscapes. See Fractal Lower Control Panel for details. Light ----- The Light button enables and displays the Light Lower Control Panel. Use this when selecting the direction and intensity of the light source. See Light Lower Control Panel for details. LOWER CONTROL PANELS -------------------- The Lower Control Panels consist of four separate Control Panels overlaid on a common space. MAIN LOWER CONTROL PANEL ------------------------ Blend ----- Blend helps reduce the coarse texture of distant parts of the landscape. If you select the Blend button, Vistapro will draw 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 rendering time. Gouraud shading gives a brush like feeling to the landscape, as if an artist painted it using oils, rather than the computer playing with numbers. Besides filtering out large polygons, it adds mood to the landscape. The foreground may appear blurry with Gouraud shading. Range ----- The range value allows you to clip away parts of the landscape which are farther away than the range value. For example, if the range value is set to 1000, Vistapro will not draw parts of the landscape farther away than 1000 meters. The primary reason for this function is to show only the parts of the landscape very near the camera, making sure that something is not blocking the view. You don't want to wait thirty minutes for a picture to render just to find out that a tree completely blocks the view. The value 0 is a special case; it disables the Range function. Otherwise the value represents the distance from the camera, at which the landscape is clipped away. Values below 100 are usually not useful. The sky and horizon are not affected by the Range function. The range function can be used to generate a special effect while executing a script file. As the camera moves around the landscape, only the parts of the landscape near the camera (within the Range) will be visible. Texture ------- Vistapro can add additional texture to nearby polygons by breaking them into smaller pieces and drawing each of the pieces as slightly different shades. This adds artificial detail to nearby areas. There are four different levels of detail: * Off * Low * Medium * High They are selected by the "O", "L", "M", and "H" buttons below the Texture label. The higher the detail level the longer a picture will take to render. PDthr ----- Dithering at the pixel level increases the apparent number of colors in the display. Vistapro 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 you can no longer recognize the picture. Normal values will range from 0 (no dithering), to 100 (a little dithering), to 300 and above (significant dithering). When a new dither value is entered, Vistapro prompts for ordered or random dithering. Render ------ This starts the generation of a new picture using the current settings in the control panels. Vistapro performs several functions while rendering. It displays its progress above the topographic map in a status window. For most functions, there is a continuously updated status count, so that you can monitor Vistapro's progress. (See Vistapro Status Window for more information.) You can abort the rendering process by pressing the ESCAPE key or by pressing and holding down the right mouse button until the rendering stops. View ---- When rendering is complete Vistapro waits for you to press either mouse button or the ESCAPE key. It then redisplays the control panel and topographic map. If you want to see the same picture again you can view it by pressing the View button. The picture will remain visible until you press either of the mouse buttons or the ESCAPE key. LENS LOWER CONTROL PANEL ------------------------ The camera lens feature represents the lens type of Vistapro's imaginary camera. Wide: The wide angle lens gives a 90 degree field of view. It allows you to see a wide area with minimal spherical distortion. The wide angle lens has a zoom 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 angle lens (about 45 degrees), or you can 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 zoom value of 32. Zoom Value: The Zoom 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 Zoom value is, the wider the field of view. The higher the Zoom value is, the narrower the field of view and the greater the magnification. The lowest valid Zoom value is 1. This is an extremely wide angle lens with severe spherical distortion. Values below 8 are generally impractical but fun to try. You can set the Zoom value as high as 30,000, but such high numbers are only useful when the camera is very far from the landscape (a million meters or so). You will probably usually use Zoom values from 16 to 100. FRACTAL LOWER CONTROL PANEL --------------------------- Random ------ Random Landscape Generation allows creation of a vast number of completely artificial landscapes. Vistapro supports over four billion random fractal landscapes. Each different number in the Fractal numerical gadget represents a different landscape. You can use negative numbers. Using a number such as -1,231,541 will create a different landscape than its positive counterpart 1,231,541. Select Random on the Fractal Lower Control Panel. Notice that a new number has appeared in the numerical gadget. The software will then proceed to create a new landscape. If this landscape is one which you may want to use again, be certain to write down the number so that you can recall it again, or save the landscape, using the Save DEM Menu Item. To recreate a desired landscape, simply reenter its number in the numerical gadget and Vistapro will create the same landscape again. This method conserves disk storage space much more efficiently than saving the entire landscape as a DEM file. Alternatively, enter any number desired into the numerical gadget and explore landscapes in this fashion. Various methods include using special dates such as birthdays (minus hyphens or slashes, i.e.. 52262 not 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 Vistapro. Like the fingerprints of the four billion inhabitants of this planet, some Vistapro scenes may look similar, but, upon closer examination, each one is individual and distinctive. Island ------ There are two modes for generating fractal landscapes, Island and Floating. In Island mode the four edges of the fractal landscape are at the same altitude. This allows you to create islands by setting the sea level higher than this edge altitude. It also will create seas surrounded by land. See the Sea function for details on its function. In floating mode, the four edges of the landscape are allowed 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 will be generated in Island mode; otherwise they will be generated in Floating mode. FrDim ----- The FrDim value controls the Fractal Dimension (height and roughness) of the fractal mountains. The 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 will generate taller, rougher landscapes. Smaller values will generate flatter, smoother landscapes. Fractlz ------- You can fractalize the current landscape to add fractal detail. If the Fractal Dimension is set to low values the effect is to smooth the landscape. If the Fractal Dimension setting is high, the landscape will become rougher. The fractal divisor buttons 1, 2, 4, and 8, immediately below the Fractlz button control the scale where the fractalizing occurs. At lower values fractal noise is added only at very small scales--the landscape will look basically the same shape, just rougher. At higher values the landscape will start looking rougher, and at larger scales may no longer resemble the original landscape. Stretch ------- The stretch function changes landscapes by vertically stretching existing features. Peaks will grow taller, valleys and pits will grow deeper. The scale at which this happens is controlled by the Fractal Divisor buttons (1, 2, 4, and 8, immediately above the Stretch button). At lower values only the smallest features are stretched. At higher values only the larger features are stretched. You can stretch landscapes over and over again to create a caricature of the original landscape. Fractal Landscape Number ------------------------ This numerical gadget located below the Random button is for entering the number of the fractal landscape you want to generate. Alternatively, it displays the random number generated when you press the Random button. Whether you enter a number or it is generated randomly, Vistapro uses the number to generate a fractal landscape. To enter your own value, position the mouse pointer over the gadget and press the left mouse button. The pointer will disappear. Type in your number from the keyboard and press ENTER. Vistapro will then generate that landscape. Note that the Fractal Dimension and Fractal Divisor values are used while generating the landscape. Fractal Divisor --------------- The Fractal Divisor buttons are the four buttons located between the Fractlz and Stretch buttons. They are labeled 1, 2, 4, and 8. The values they represent are used by the fractal generation routines. When Vistapro generates a fractal landscape (after you press the Random button 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 Fractalize and Stretch functions the divisor value represents the frequency at which the existing landscape data is sampled in order to generate the new landscape. See the sections for Fractalize and Stretch for more details. LIGHT LOWER CONTROL PANEL ------------------------- Light Source Direction is the direction from which the sun is shining, and you use it in combination with the exposure, contrast, and shadow settings to determine the location and depth of shadows when generating an image. This function "moves" the sun. Whenever this panel is selected several concentric circles will be drawn in black over the landscape. These circles are reference points so that you can visually estimate the declination of the sun. The circles are labeled with the declinations that they represent, 75, 60, 45, 30 and 0 degrees above the horizon. A line (the Sun Vector) will be drawn from the center of the bulls eye out 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. You should 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. 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 will be shining. When using one of these positions the sun is at 45 degrees 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 you can see the Sun Vector (the line radiating from the center of the "bulls eye") change to indicate the new direction. Custom ------ The Custom button gives you complete control over the direction and angle of the light source. Selecting this button causes the Sun Vector to follow the mouse pointer as it moves around the screen. This represents the position of the sun in the sky. Think of the line as a stick pointing at the sun from the center of the landscape. Since you are looking down onto the landscape from above, the longer the stick is, the closer the sun is to the horizon; the shorter the stick is, the closer the sun is to directly overhead. The stick points in the direction of the sun. When you have located the desired direction and angle, a single click with the left mouse button locks this 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. Exager ------ The Exager (Exaggeration) button enables exaggerated shading. Imagine a ball in front of you, with a light shining on it from above. The top of the ball faces the light, and appears very bright. Points farther down the sides of the ball reflect less light and appear darker. Halfway down the side, the light no longer shines on the surface, and it is in shadow. Exaggerated shading increases the rate at which the shades darken around the sides of the ball. This technique can add detail to the image by exaggerating small irregularities on the landscape. You will probably want to disable this function when setting the sun at low declinations, since the exaggeration makes all the flat areas appear very dark. Azimth ------ Use the Azimuth gadget to set the direction (in degrees from due south) from which the sun shines. Zero degrees is due south, 90 degrees, due west, 180 degrees, due north and 270 (or D90) degrees 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 from the horizon from which the sun shines. Zero degrees of declination puts the sun right on the horizon, while 90 degrees put the sun directly overhead. This is similar to the way Pitch is measured for the camera. Rough ----- The Rough button sets the apparent roughness of the landscape when rendered. Vistapro accomplishes this by adding a scaled random number to the shade of each polygon, so that some of the polygons will be darker than normal and some will be lighter. By doing this, large flat areas will appear to have a little more detail than they otherwise might. To set this value, click the mouse on the Light button located on the Middle Control Panel. Click the mouse pointer on the Rough numerical gadget. Change the number from the keyboard and press ENTER. Useful values range from 0 to 300, with higher values giving rougher appearing landscapes. Very large roughness values result in unnatural shading. Shadow ------ Vistapro has the ability to render landscapes with shadows. True shadows are very difficult and time consuming to render so Vistapro uses a quick, less precise method. Only the landscape itself casts shadows; trees do not cast shadows. Shadows will not be cast outside the area of the topographic data. Shadows are enabled when the Shadow button is depressed. The Shading phase will require more time when Shadows are enabled. *** End of Chapter Four ***