VTP Terrain Library (vtlib)

Overview

The vtlib C++ library provides:

• An abstraction layer, so that any of a number of scene graph libraries can be used identically.
• The ability to procedurally construct and render interactive 3D terrain from geospatial data sources.

Features include:

• Continuous LOD for regular grid heightfields
• Applying geospecific texture maps
• Skydome with sun, moon, and stars
• Vegetation using plant billboards
• Procedurally-generated Roads
• Procedurally-generated Buildings
• Procedurally-generated Linear Structures (Fences, Wall, Hedges, Berms..)
• Several kinds of 3D navigation
• Detail texture (still experimental)
• Importing 3D Models
• Ray-Heightfield intersection testing
• Structure shadowtextures (still experimental)

It is built on top of:

1. the vtdata library which provides the geospatial data types, 2D operations, and most file IO
2. any one of several 3D scene graph libraries
3. Stefan Röttger's libMini CLOD library
4. OpenGL

Class Documentation

There is automatically generated documentation for the classes.

Usage

• Some description of coordinate systems and frames of reference.
• How to load and draw a simple terrain.
• How to allocate and free vtlib objects.
• How to load and place 3D model files.
• How to create a custom node to draw your own OpenGL geometry.

Scene Graphs

vtlib has been ported to many different scene graphs over the years.  The most advanced port is to OSG (OpenSceneGraph) since 2001.  Each vtlib port has a name corresponding to the underlying library:

• vtopensg is vtlib on top of OpenSG.  See the vtopensg page about it.
• vtosg is vtlib on top of OSG.
• vtplib is vtlib on top of PLIB / SSG, historical.
• vtpsm is vtlib on top of PSM, historical.
• vtsgl is vtlib on top of SGL, historical.

Issues

• Z-Buffer Issues with roads and water
• Some degree of support for Vehicles