CityDiscoverer - Terrain Creation Parameters

Elevation

Elevation Grid Grid Filename The BT file to use for elevation.
Terrain 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.
Use strips/fans Allows the LOD algorithm to use triangle strips and fans while rendering.  With some algorithms, this may increase rendering speed significantly, and also may also introduce some limitations.
Elevation TIN TIN Filename The TIN file to use for elevation, instead of an elevation grid.
Grid Tiles Tileset Filename 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 indicated vertex count.
RAM cache size When tiles are loaded from disk, they are stored in a cache in RAM.  As the camera moves around, tiles which are not needed remain in this cache, which avoids loading them from disk again while the program is running.
  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

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
CityDiscoverer will create a texture for you, and fill it with false colors based on elevation.
4x4 Tiled Texture You provide a single large square image file, and CityDiscoverer will break it up for you, at runtime, into a set of 16 tiles (4x4).  The filename is made up of three parts: the prefix (e.g. "hawaii_"), the image size (e.g. "4093") and the format (either BMP or JPG). The dialog lets you specify the prefix and tile size, and it computes and appends the image size.
Tileset Filename 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, CityDiscoverer 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.
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, although eventually it should be multiple textures based on type of ground cover (dirt, rock, grass, etc.)

Culture

Plants Source file The name of a VF (Vegetation Format) file which contains the plant instances for this terrain.
Visibility distance Distance at which plants are visible.
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.
  Terrain-specific
 Content
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".
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.
Paging Activate for large numbers of structures. Page out Distance: Distance at which structures are paged out of memory if structure paging is activated
Maximum Structures: Limit for structures loaded into memory regardless of paging distance.
Shadows Resolution for shadows cast by buildings. Darkness will rule the amount of the original ground texture that is still visible. 1 means black.

Sky & Ocean

Ocean 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.
Depress Ocean Set this option to change your elevation 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.
Depress Ocean Level The level, in meters, to artificially depress the ocean.  -40 meters is a typical value.
Sky Dome (Source file) The filename should be a 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.
Artificial Horizon If true, a flat "horizon" object will be placed between the edge of your terrain and the base of the sky.
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
 Color
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.

Abstract Layers

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 SHP file that is in a "PointData" folder on your data path.

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.
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.

Miscellaneous

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.
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.
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.
Time Initial Time of Day Hour, from 0 to 24, for the time of day when CityDiscoverer 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.

Scenarios

(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.