first of all ,sorry for my english I'm making my parts with 3dsmax(2013),and export .DAE to game,there are some problems: 1.my parts don't have hige-light effect when mouse over them,looks like Collision mesh problem,but surface attach works fine. 2.when my part2 (with 4 nodes) stack to part1(with 2 nodes),other 3 nodes of part2 disappeared,part1 is fine;when surface attach,all nodes are fine. 3.when launched,aall my parts fall through ground about 1/4 4.node_vector give me lots of"e-007",like this: node_stack_back010 = 9.53674e-007, -0.999999, -5.96046e-007, 0.0, -1.0, -2.8213e-007 my Collision meshs are simple,like box or Hexagon.I don't know why this happen.please help.