Dynamic evaluation and modification methods against aggressive mesh hierarchy models
针对层次式累进网格模型的动态评估与调整

For progressive mesh models, a method of dynamic evaluation and dynamic modification is proposed to design a reasonable model structure for deformations. The evaluation specifies the levels of detail and mesh regularity and the modification changes of the topological and geometric mesh structure. The global levels of detail for all nodes of the active vertex tree are decided by the view frustum, the surface normal, the screen-space geometric error, and the deformation contribution. Topological regularity is evaluated by geometric properties. A series of modifying operations are used to correct the topological and the geometric mesh structure, where topological modifications include a global pre-construction of a mesh model and real-time adjustments on the local mesh connectivity and geometric modifications using Laplacian smoothing to change the vertex position and to eliminate deformation distortion. Guided by the evaluation results, proper modification is selected for a specified submesh, which guarantees the real-time efficiency and adaptivity. This proposed approach has been applied on progressive mesh models to prove the performance.