ABSTRACT
This chapter describes an implicit texture parametrization system to solve the problems that called packed Ptex. It focuses on the Ptex method developed by Disney Animation Studios for production rendering. Ptex associates a small independent texture map with each face of the mesh. Displacement mapping adds geometric detail to a coarser mesh. In classical displacement mapping, there is just a single scalar per texel. However, vector displacement is pursued, which uses a 3D vector to specify displacement. Packed Ptex enables the main advantages of the original Ptex method while enabling real-time use. There are two barriers to real-time performance in the original Ptex method. First, it's typically not practical to have an individual texture for each primitive. Second, the indirection required when a filter kernel crosses from one face to another is costly in performance, and precludes the use of any hardware texture filtering.
