Hi Russ, I've found two memleaks in collision_trimesh_trimesh.cpp. there are at lines 492: firstClippedElt = new dVector3[firstClippedTri.Count]; 593: secondClippedElt = new dVector3[secondClippedTri.Count]; These pointers are allocated in the cycle for (int i = 0; i < TriCount; i++) but deleted only after it. -- Best regards, Anton