Enviro - Terrain Creation Parameters


Grid Grid Filename The BT file to use for elevation.
  LOD Method Choose from several implementations of published Continuous LOD algorithms.  Unless you are an expert user, it is recommended to use only Roettger.  The others are historical or of interest to algorithm specialists.
Triangle Count Algorithms will adaptively adjust detail to meet this indicated triangle count.
TIN TIN Filename The TIN file to use for elevation, instead of an elevation grid.
Grid Tiles Tileset .ini file The .ini file which describes a set of elevation grid tiles.  See tileset documentation.
Vertex count target Rendering will adaptively adjust detail to approach this vertex count.
Use multithreading This option is recommended, as it should increase speed/smoothness on most modern computers.
  Vertical Exaggeration A value of 1.0 draws the terrain with real-world proportions.  A value of 1.5 exaggerates height by 50%, and so forth.


Texture No texture Your terrain will be white and plain.
Single texture The indicated texture will be placed over the terrain.  It must be a power of two in dimension, and be within the limit of your 3d hardware's maximum texture size.
Derive texture
 from elevation
Enviro will create a texture for you, and fill it with false colors based on elevation.
Tileset .ini file The .ini file which describes a set of texture tiles.  See tileset documentation.
Mipmapping This will reduce aliasing, at the expense of using more texture RAM.  There might also be an impact on rendering speed, depending on your graphics hardware.
Request 16-bit Normally, textures are processed as 24-bit images.  This options tells the 3d hardware that it is OK to use only 16-bits, which can save significant texture RAM.
Precompute lighting At runtime, Enviro will make the terrain texture darker/lighter to simulate the sun's light.  This is not necessary if you are using a Geospecific texture which already contains shadows.
Lighting factor Use this scaling factor to make the precomputed lighting more pronounced or more subtle.  1.0 is the standard value.
Cast Shadows If true, then the terrain shading will use a ray-casting approach, so that the terrain casts shadows onto itself.  If false, then simpler (dot-product) shading is used.
Retain loaded
 texture in memory
If you are loading a texture from disk and shading it, this option will keep an unshaded copy of the texture in memory, so that you can change the shading at runtime without waiting for the texture to load again.  If this is not what you are doing, leave the option off.
Detail texture   Currently only works with the McNally CLOD option.
Will attempt to put a second, high-frequency detail texture over the whole terrain, faded by distance so that it is only visible close to the viewer.  Currently this can only be a single texture.

Plants and Roads

Plant Layers (Source files) Any number of VF (Vegetation Format) files which contains the plant instances for this terrain.
Visibility distance Distance at which plants are visible.
Use Shaders for Plants This option is around 5x faster, but you won't be able to edit the trees, and some other small limitations.
Roads Source file The name of a RMF (Road Map Format) file which contains the road information.
Ground offset All the roads centerlines will be elevated by this amount above the terrain.  This can help to avoid collision or occlusion problems between the road and terrain.
Visibility distance Distance at which roads are visible.
Texture-map roads Set this for textures (pavement, roads stripes, etc.)
Road culture Set this for culture (such as stop sign and stop lights) automatically generated from the traffic information in the RMF file.
Include... You can use these options to indicate a subset of the roads to create, e.g. only Paved roads.


Structure Files (Source files) Any number of VTST (.vtst, Built Structures) files, containing the Buildings, Instances, and Fences for this terrain.
Visibility distance Distance at which structures are visible.  Structures further than this distance from the camera will not be rendered.
A content file (.vtco) which contains additional content items specific to this terrain.  For example, if the terrain is in Australia, you might have a set of Australian content items specific here, "Australia.vtco".
Shadows (on) Dynamic shadows will be cast from the structures onto the terrain (and other structures).
Resolution The resolution of the shadow map texture.  Shadows are better defined (crisper) when you increase this number.  Older or less-powerful 3D cards will only support up to 2048.
Darkness A value from 0 to 1 for shadow darkness.  Older 3D cards do not support variable darkness, so they will ignore this value, and shadows will always be black.
All structures cast
 shadows by default
If true, then every structure is automatically set to casts a shadow.  If false, then no structures cast a shadow unless you tell them, for example with right-click menu, "Toggle Shadow".
Recompute shadows
 every frame
If true, then the shadows are truly dynamic.  If false, shadows are only recomputed periodically, such as when the sun moves.  There is a performance cost to this option, depending greatly on your CPU and GPU.
Limit shadow area The shadow resolution must be stretched over the area of all structure casting a shadow, so to increase sharpness, you can limit the area to a given number of meters, relative to the spot on the ground where the camera is looking.
Paging (on) Instead of all structures being created when the terrain loads, structures are loaded and unloaded dynamically ("paging") as the camera moves around.  This allows you to quickly load terrains with huge numbers of buildings, and fly around without using too much memory
Maximum structures When the number of loaded structures exceeds this number, far-away structures will be unloaded ("paged out") to conserve memory.  A typical value is 2000.
Page-out-distance This distance indicates when a structure is far away, so that it can be paged out.


Sky & Water Ocean Plane Set this option to create a single, large, flat "ocean" surface which intersects the terrain.
Ocean Plane Level The is the elevation, in meters, at which the ocean plane will appear.  Normally you would set this to either 0 (exact sea level) or slightly lower (e.g. -20) which can help to avoid Z-buffer problems between the ocean place and some terrains.
Water Surface Loads an elevation TIN as a water surface, which usually intersects the terrain, so the water surface is visible when it is higher than the ground surface.  It will be colored like water (blue and semi-transparent).
Depress Ocean Modifies your elevation, at load time, such that all points at "sea level" (elevation = 0 meters exactly) are artificially displaced.  This can be useful combined with "Ocean Plane", since many Elevation data files represent the ocean as "sea level", this option will restore some depth to the ocean, so that it will not intersect the Ocean Plane.
Another useful effect of this option is that it produces a "cliff" at the shoreline, which can help the CLOD algorithm to maintain the shoreline.
Sky Dome The dome will be drawn using the specified PNG or JPG file with a hemispherical image of the sky.  All files found in the "Sky" folders on the data path are available for you on the drop-down control.  If the filename is blank, then sky will be drawn using vertex colors, using time of day (blue during day, orange during sunset, black at night, etc.)
Fog Fog causes an evenly distributed haze to appear, gradually increasing from transparent at the camera, to opaque a the given distance from the camera.
Scene Background
This is the color that appears behind the terrain and skydome.  If you use the skydome and artificial horizon, you won't see the background.
Time Initial Time of Day Hour, from 0 to 24, for the time of day when Enviro starts the terrain.
Time Moves If set, then time cause the sun and sunlight to move, day and night to affect the sky dome, and the moon and stars to move at night.  Note that currently the lighting on the terrain surface itself is not updated dynamically - it will remain at the initial time.
Faster than real Watching the sun move across the sky at real-world speed may require too much patience.  Try setting this value higher than 1 (e.g. 1000) to see time move rapidly.


This is the place to specify features that don't correspond to a real, visible aspect of the physical world.  Example: place names, national boundaries, GPS tracks, etc.

Abstract Layers <Files> The file to read features from.  This can be any vector data file (SHP, DXF, etc.)

To add files, double-click.
To remove files, select them and press <Delete>.

Supported data types are: 2D Points, 3D Points, 2D Polylines, 3D Polylines, 2D Polygons.

Style To set the style for a layer, select it and press the Style... button.  The Style Dialog lets you indicate how you want your abstract features to be drawn: color, text label, height above the ground, and so forth.
Image Layers <Files> You can have one or more images, loaded and draped on the terrain, in addition to the base ground texture.  Each should be a GeoTIFF file (or other format, with a World file) in a GeoSpecific data folder, with the same CRS as the terrain.

To add files, double-click.
To remove files, select them and press <Delete>.

The number of Image Layers you can use is limited by your 3D graphics card's number of fixed-pipeline texture units.  Commonly, this is 3.


Window Overlay Image file You can specify an image file which will be drawn as an "overlay" over the 3D window at runtime.  This can be useful for things like a legend or overview map.
Placement Where to place the Overlay Image, in pixel coordinates, relative to the bottom left corner of the 3D view.  You can use negative values to indicate a position relative to the other side of the window.
Example: -30, 10 is a position 30 pixels from the right side of the view and 10 pixels above the bottom of the view.
Terrain overview map The terrain texture will be shown as a clickable map in the lower-left corner of the 3D view.  Only supported if your texture is simple, not a tileset.
Compass A compass will appear in the upper-right corner of the 3D view, showing which way you are facing.


Navigation Style See mouse navigation for a description of the various styles.
Minimum height
 above ground
The camera will be kept this height above the ground at all times.  If you need to go under the ground, use a negative value.
Navigation speed This is a factor used to scale the speed of your motion when using the mouse to navigate.  You can change it on the fly once the Terrain View is running.
Velocity Damping For the Terrain Flyer with Velocity, this sets how much damping your motion has, from 1 to 10.
Default locations file You can load and save any number of Locations to a file.  This option lets you associate a specific file with a terrain.
Initial Camera Location If you have a location file, you can select one of its locations as the starting point for the camera, the first time the terrain is loaded.
Near Clipping Distance Otherwise known as "Hither", everything closer than the Near Clipping Distance will not be drawn.  Be careful not to make this value too small, or you may see Z-buffer problems, depending on your graphics card.  If you do see Z-buffer problems, try increasing your Hither distance at runtime.  If that fixes the problem, you can make the change permanent using this startup property.
Animation Paths (VTAP files) Any number of .vtap files which will be available during runtime.


(List of Scenarios)   A scenario is a set of visible layers.  You can use the self-explanatory buttons (New, Delete, Edit, Move Up, Move Down) to create a set of Scenarios.  At runtime, you can switch between these scenarios to show different sets of visible layers.
For example, you could create two scenarios called "Existing" and "Proposed" and switch between them easily.