Technical Section Mesh refinement with color attributes $

Abstract

Although many sophisticated solutions have been proposed to reduce the geometry complexity of a 3D mesh, fewof these take into account color and texture fields, which are fundamental for a visual appearance of high quality. We propose here an innovative solution which combines the concept of hierarchy in refining a mesh with color attributes with mesh regularization. It operates subdividing recursively the faces of a 3D mesh, which was previously simplified according to geometrical criteria only. Newvertices are introduced by splitting a face until a maximum color error is achieved. The error is evaluated in CIE-L u v iso-perceptual metric. Splitting is carried out using a newstrategy, which chooses between either binary or quaternary subdivision schema, in order to achieve 3D mesh regularization. In this respect our method improves other hierarchical subdivision techniques (applied for example to radiosity and height fields). If the unsimplified version of the mesh is available, the procedure positions the newvertices on this mesh, decreasing, the topological error besides the color one. The method presented here is quite general and allows to create models of high pictorial quality ( 20,000 faces), which can be manipulated in real-time on machines with no hardware accelerator for texture mapping. Main strength of the method is locality, which allows very fast operations as well as the possibility of local refinements. Results showhow, at the expense of fewmore polygons, the final appearance of the model can be greatly improved in a very short time. The produced models are suitable to progressive transmission: firs