I’d like to have a surface (extruded plane) with material that projects onto another surface beneath it (could be a wall, ceiling, floor, terrain, etc.)
Imagine a terrain mesh with terrain material, and a decal mesh with foot steps (or oil spill puddle) material (colored texture) placed slightly above the terrain mesh. The decal texture needs to be projected to the terrain mesh to conform to it (and perhaps when terrain texture is baked, the decal should stay on the baked terrain texture).
Is it achievable with Cycles ?
How do I set up this contraption ?