I have three rigidbodies. One is a box, another is a sphere and the last one is a convex shape. They are dropped on the static plane with 0 mass. But how come they located on different heights finally? I really have no idea. Are there any bugs or setting errors? I use away3dphysic and away3D 4.

Thank you for any help.

Does your convex shape have any scaling?
try baking the transform into the geometry.
eg
yourMesh.bakeTransformations();
then add your mesh geometry to the convex shape

Thanks John. Maybe the problem comes from that collision margin thing in bulletphysic. bakeTransformations helps nothing. I am going to scale the models ten times larger in blender first. Many thanks.