Procedure models for generating three-dimensional terrain

A method for generating arbitrary terrain models, including trees, bushes, mountains, and buildings, is described. Procedure models are used to combine fundamental data elements in the creation of unified objects comprising the terrain model. As an example, a procedure model to generate arbitrary trees of various species is implementation. These are the generation of the low level data elements, specification of input parameter requirements, and a brief explanation of the algorithmic structure. Terrain images rendered by this process are included, as are diagrams and illustrations explaining the procedure model organization. Comparisons with previous work are made.