The VRayPtex node allows the you to load and use PTex textures with V-Ray. PTex is a mapping system that applies a separate texture to each face of a subdivision or polygon mesh and therefore requires no UV assignment. A PTex file can store an arbitrary number of textures along with mipmaps and adjacency data used for filtering across face boundaries. For more information on the PTex concept, see the Notes section below. See also the tutorial on Rendering PTex Textures from Mudbox and on Rendering Vector Displacement with Object-Space PTex. The example shown here has PTex textures for the Diffuse and Bump channels of a V-Ray Material
