Collision : getPolyList/buildPolyList... which one do I want?

EDIT: I've re-classified this thread as informational, and not reporting a bug. The solution for my problem was to rely on buildPolyList rather than getPolyList. getPolyList generates tetrahedrons from each triangle so that the GJK solver (that powers the vehicles physics) will work properly.

I've been debugging an issue with player collision in Torque3D, and believe that the OPcode poly soup may be doing weird things.

For reference I'm using a modified version of the 3D Action Adventure Kit from Ubiq visuals that I've ported to Torque3D.

Most of the functionality of the player worked out of the box with a DTS counterpart, except for the ledge grabbing bit.

I've been down a number of bad roads trying to figure out why this could be, and then realized that by manually calling buildPolyList instead of relying on Convex::getPolyList functionality fixes the issue.

// GOOD
pConvex->getObject()->buildPolyList(&polyList, plistBox, SphereF());

// BAD
pConvex->getPolyList(&polyList);

From all the tracing into the code I've done, it seems like both of these should be returning the same data, but here's what I've found :

getPolyList

buildPolyList


Looking a bit further into why there is a discrepancy, I stumbled across this function that appears to be what is generating the pyramid shape geometry that's being passed into the working list.

bool TSMesh::buildConvexOpcode( const MatrixF &meshToObjectMat, const Box3F &nodeBox, Convex *convex, Convex *list )

Thanks for your thoughts.



Edit: Props to KillerBunny for halping me understand what was going on.