How do I do Collision Mesh?

#1
The collision mesh is Col-1, the visible mesh is Trunk400. Note where they are linked and where their markers are linked (Collision-1 and detail400). The collision mesh *must* be a closed, convex volume (best to keep it under 30 triangles).

#2 @Matt
The collision mesh needs to be a closed convex shape, and as Matthew stated it is best to keep its count as small as possible.

Basically you need:
1) A dummy node named collision-#, where # is a number between 1 and 8. This needs to be linked to base01.
2) The actual collision shape named col-#, where # is the number that matches your collision dummy number. This needs to be linked to start01.

#3 Wow that really works great thanks i needed that

#4 I have gone through all the steps stated above to give my object collision. However, when I load my object in game, I am still able to walk through it. Any idea what my problem is? Thanks in advance.

#5 I do not see a problem. Are you keeping your collision meshes in the 1-20 polygon range? And are you keeping them convex? If you are, than I suggest you try dividing your collision meshes into smaller pieces.