Inspired by Eric Mootz “3D Texture Coordinates on Polygon Mesh Sequences”, i am presenting a minimal Setup for Houdini. The mentioned technique is tackling the problem of using UV-Information in a changing mesh topology. Consider a Fluid-Mesh which is deforming over time, the Point-Count is constantly changing and UV Information are lost. By using the velocity attribute of a fluid-simulation, we can do an averaged lookup into the previous frames mesh and derive uv attributes.
What the solver does:
The solver takes the current Position of the current Mesh in the Frame and calculates back with the Velocity attribute the current Points Previous Position. (Position – (Velocity / FPS)). In Ideal case, we will find the previous Points exact Position, but doing a search in a point-cloud will guarantee that newly spawned Points can get as well a close position representation. This new calculated Point is then used to make a lookup in the previous Mesh’s (Frame -1) uv Channel to get again an average uv-coordinate attribut for the new Point.