like trees? i can't use a bounding box, because the upper part of a tree is much bigger than the trunk. the player shoud be able to walk aroung below the tree, maybe on top of the tree (not realistic, but fun), but must not be able to walk through it.
Try using a less complex, hidden mesh as the collision geometry.
looks like i'll have to write a "getcollisionboxesforcomplexspatials"-method