Simulation And Visualization On Space-Time Distribution Of Forest Based On Environment

The Forest dynamic changes have two distinct characters: long time scale and large space scale, which make forestry research more difficult. In Virtual Forest Environments, complex forest objects are constructed; the laws of stand growth are presented and analyzed with computer graphics technology and forestry knowledge. So Virtual Forest Environments can provide a new way for forestry research.Presently, there are few models of forest space-time distribution constructed based on the growth, mortality and regeneration of single tree. And the output results are mainly in diagram form, which are not intuitionistic. In this thesis we develop our forest space-time distribution model based on the forest gap model by the environmental factors, especially the specific terrain situation. And then the visualization module renders the terrain scene with digital elevation map (DEM), and visualizes the trees' distribution based on the forest evolving result. The main work of this thesis is as follows:1. The advancement of related research fields is summarized detailedly from three aspects, i.e., forest growth model and forest management model, geometric modeling and rendering of single tree and forest visualization. The drawback of above research is also pointed out.2. Based on the current tree growth model, we construct out tree growth model in which the influence of environmental factors is considered.3. Based on the tree growth model in forest environment, we construct our forest evolving model taking mortality and regeneration of single tree in account.4. Based on the distribution and growth situation of trees we render the forest scene with LOD and Billboard technique.5. The thesis implements the prototype system of space-time distribution of forest based on environment with the model referred above.