Terrain Geomorphing in the Vertex Shader

Abstract

Terrain rendering has heretofore been computed by a CPU and rendered by a combination of CPU and GPU. It is possible to implement a fast terrain renderer which works optimally with current 3D hardware. This is done by using geo-mipmapping which splits the terrain into a set of smaller meshes called patches. Each patch is triangulated view-dependently into one single triangle strip. Special care is taken to avoid gaps and t-vertices between neighboring patches. An arbitrary number of textures can be applied to the terrain which are combined using multiple alpha-blended rendering passes. Since the terrain?s triangulation changes over time, vertex normals cannot be used for lighting. Instead a pre-calculated lightmap is used. In order to reduce popping when a patch switches between two tessellation levels geo-morphing is implemented. As will be pointed out later, this splitting of the terrain into small patches allows some very helpful optimizations.

Reference

D. Wagner: "Terrain Geomorphing in the Vertex Shader"; in: "Shaderx2: Shader Programming Tips & Tricks With Directx 9", issued by: Wolfgang Engel; Wordware Publishing, 2003, ISBN: 1556229887.

BibTeX

@incollection{TUW-138077, author = {Wagner, Daniel}, title = {Terrain Geomorphing in the Vertex Shader}, booktitle = {Shaderx2: Shader Programming Tips {\&} Tricks With Directx 9}, year = {2003}, organization = {Wolfgang Engel}, publisher = {Wordware Publishing}, url = {http://www.ims.tuwien.ac.at/media/documents/publications/Terrain_Geomorphing_in_the_Vertex_Shader.pdf}, isbn = {1556229887}, keywords = {Realtime Rendering, DirectX, Shader} } Click into the text area and press Ctrl+A/Ctrl+C or ⌘+A/⌘+C to copy the BibTeX into your clipboard… or download the BibTeX.