I need to code a function that basically traces the path a sphere would roll when placed on a triangulated terrain. The image below shows the problem, but I haven't got a clue how to work with vectors in order to find a solution.
Pseudocode-wise, I'm looking for:
def gravity_trace(face_ABC, point_D): ... return X
I honestly don't know how difficult it will be to fill in the ... above. I'd appreciate any and all help I can get. My math skills are terribly rusty and I have never worked with vector math before.