TerraFirma also has the ability to create synthetic terrains from pre-defined algorithmic formats such as fractal, hill, and island generator as well as common heightfield formats such as DTED and USGS STDS. Each of the algorithm generators is based on some stochastic process and its corresponding well-defined parameters. A third party developer can add his own synthetic terrain generation algorithms. The TerraFirma API contains a plugin interface for defining terrain texturing methods. Methods defined in version 1.0 of TerraFirma include: Texturing based on terrain attributes such as height and slope Geo-typical textures Geo-specific textures

Once a terrain has been generated, the developer can then populate the terrain with vegetation, structures, and miscellaneous objects (e.g. rocks, boulders, vehicles, etc.) via vegetation maps, random feature placement, and point-and-click.

• One of the most unique features of TerraFirma is its object-oriented plug-in interface. This interface allows TerraFirma to be infinitely expanded with respect to the formats it can import, formats it can export, and ways it can apply textures to the terrain. The plug-in interface is also easy to expand to include methods of terrain analysis. The plugin interface allows third-party developers to extend TerraFirma beyond these basic capabilities.
  
  Current plugin interfaces include:
  • Heightfield Generation Plugins
  • Import Plugins
  • Export Plugins
  • Texturing Plugins

Current heightfield generation plugins include:
• Random hilly terrain generator
• Random island terrain generator
• Fractal-based terrain generator
• DTED
• USGS STDS
• BMP


• Generic and expandable vegetation definitions
• Generic and expandable structure definitions
• Generic and expandable road definitions
• Point and click interfaces
• Random population of terrain regions with vegetation
• Terrain vertex editing for fine tuning regions of terrain