Raycasting is a very important concept to understand in computer graphics. Basically raycasting is like aiming a laser pointer along a vector and seeing if the beam hits something. Disney Studios made a great video that explains raycasting in the context of rendering https://www.youtube.com/watch?v=frLwRLS_ZR0. In the past I have used cMuscleKeepOut nodes to cast rays to see if they collide with a nurbs surface or mesh. This is a decent technique and is the only technique tha