I made an object that is like a tunnel, I gave it collision and bla bla bla. But I always falll through the collision in the object in certain places. I have redone the collision many times but it never works, just a hole in a different spot. Does anyone know how to fix this?

try to make a msh.option file thats named like your .msh
and write: -donotmergecollision into it, if that doesnt work, try -keepcollision

Thanks, but it didn't work... Any other ideas?

In xsi select the collision mesh, then on the side menus go to modify polygon triangulate (sorry doing this from memory)
that will sometimes help with the collision.

its already triangulated

So you are saying it is already triangulated in XSI?

What version of XSI are you using (or conversely what are you using to export to msh)?

If you are using version 5.11 and pandemic exporter you could make collision primitives for the floor, or a series of them if it is an irregular shape just make sure there are no gaps between primitives.

If all else fails, he could just put invisible collision blocks beneath the floor of the tunnel, though this is just a hack job remedy and not really a fix.

im using fnd 5.11. So the collision primitive thing, how do I do this?

They are explained in the art_guide.doc that came with the modtools, but basically they are primitives (cubes, spheres and cylinders) that are sized using the creation pop up window only (exception is a cube can be scaled) They do not get frozen either model wise or transform wise. They have a naming convention of p_-svbot-nameofprimitve

The svbot are the different kinds of in game things that will react with the collision mesh. These are once again explained very well in the doc. But just quickly if you left out the o from the string the collision mesh would affect (or be affected by) soldiers, vehicles, buildings and terrain but ordnace would pass though it.