There is a bug in the way projection from a camera is handled. If I project from a camera onto a flat surface that is square with the camera, it works fine. If the surface is rotated with respect to the camera, the image distorts in a strange way.
I may have spoken too soon on this… I think the problem was that I was projecting onto a surface that consisted of a single polygon.
The issue here is the Math that the Texture SOP uses doesn’t work with modern GPUs, as they do their on perspective correction when interpolating texture coordinates (the Texture SOP code is back from Houdini for off-line rendering).
I just added a new feature to the Phong MAT that allows each map to be textured using Screen Space Coordinates that are created automatically on the fly by the shader. I’ll be in the next build.