Research And Implementation Of Rapid Shadow Generation And Rendering Algorithm For Tree Model

As an important visual feature of trees, shadows are very important for keeping the visual fidelity of the rendering result, and the shadow rendering speed affects the whole scene's rendering speed significantly as well. So the rapid shadow generation and rendering algorithm for tree model have important meaning. A tree shadow generation and rendering algorithm is proposed in the paper, which especially fits to the widely used Billboard tree model. Based on Shadow Map, the algorithm uses a depth transformation method to solve the self-occlusion problem of Billboard, and uses shadow map filtering together with screen shadow map filtering to realize the rendering of tree's soft shadow. Besides, graphics hardware feature-Multi Render Targets (MRT) is used to optimize the algorithm process.In the paper, Billboard Tree models taken as experimental objects are from a widely used tree engine, SpeedTree, and experimental results show that the shadow of Billboard tree model generated by our algorithm has good view reality, and the algorithm is of high efficiency.