Slide 2 - Build Terrain

This exercise teaches you how to create a complete paged-terrain database without textures.

Tweak Tessellation

This series of instructions teaches you how to tweak preview mesh tessellation.

  1. Examine the hierarchy.
  2. Right click over the modifier named GeometryLayer and select Tessellation: 32 from the listed options.
  3. The worksheet looks like this: This is a picture of the worksheet.
    The terrain has much more form and shape. You can also see that the mesh correctly represents the DEM/GEOCELL terrain values. If you look at this area in an atlas, you see a large flat plane with mountains in the lower left. This preview contains 32×32 polygons which means it will create a terrain database with a minimum of 1024 nodes. That's a bit too much for right now!
  4. Right click over the modifier named GeometryLayer and select Tessellation: 8 from the listed options.

Configure The ExportOptionsModifier

Command line or dialog-based terrain generation tools use text strings or dialog box values to configure terrain generation options. Scenome uses an ExportOptionsModifier to configure terrain generation settings.

  1. Examine the hierarchy.
  2. Double click the modifier named ExportOptionsLayer.
  3. This displays modifier properties in the property editor. This is a picture of the ExportOptionsModifier property sheet.
  4. Scroll down to the Create Tiles With These Tessellation Values property group.
  5. Set Output Rectangle Tessellation X and Y to 32.
  6. Scroll down to the Create This Many Levels-Of-Detail property group.
  7. The modifier is configured to create 3 levels-of-detail.
    • The first level-of-detail uses no simplification.
    • The second level-of-detail uses 50% simplification.
    • The third level-of-detail uses 75% simplification.
    The preview mesh is tessellated to 8×8. This tells Scenome to create a terrain database composed of 64 individual terrain meshes. The ExportOptionsModifier Output Tessellation parameter tells Scenome how much tessellation to use in each output mesh.

Build The Paged Terrain Database

Command line or dialog-based terrain generation tools use text strings or dialog box values to configure terrain generation options. Scenome uses the ExportOptionsModifier to configure terrain generation settings.

  1. Examine the hierarchy.
  2. Right click over the mesh node named Lat: [45.00 to 46.00] Long: [-110.00 to -109.00] and select Create Terrain from the listed options.
    Scenome builds a paged terrain database and begins paging the parametric meshes from disk. While it is doing this, Scenome uses another thread to perform simplification in real-time. You can check its progress in the status bar. Because this is a 64 node database with three levels-of-detail, Scenome has to build 192 individual meshes. Don't worry, this doesn't take very long, even if you decide to build a paged database with 1024 or 4096 nodes.
  3. At this camera position Scenome displays the medium and low levels-of-detail. The worksheet looks like this. This is a picture of the worksheet. Here you can see sixty-four individual terrain quadrants. At this camera position Scenome only displays the low level-of-detail.