Where does the OrdnanceCollision line take the msh for collision from? I've tried using objects' names, p_sphere, Collision, CollisionMesh, but none of them have worked. I'm assuming it works similarly to how a shadow mesh works, so I'd need to go into the object to see what the collision is called.

I'm wondering how to use the object's mesh as an ordnance collision.

https://sites.google.com/site/swbf2modt ... /art_guide

scroll down to collision. I think each thing has to have seperate collision meshes. And I think all soldiers just use some weird cylinder or something.

I have always thought it ordnance collision to be only the dummyroot null (a single point inside all objects). EDIT: looks like ordnaces have collision mesh, according to the link.

You can't create custom collision for units; they all use the same basic, hard-coded collision primitives. With that said, you can, however, scale and offset the collision meshes via the units' ODFs. Here are the parameters:
Example of some of them being used (taken from Geth Prime in MEU):
You can view the collision by going into the debugger, typing RenderOrdCollision (I think) into the console, and viewing the model in Freecam mode.

@MileHighGuy: Thanks. I looked around that page a bit and it's quite useful. However, I don't have XSI right now so I can't use too many of those techniques.

@Marth8880: Thank you! It works like a charm. RenderOrdCollision really helps visualize things as well and it's proven to be quite useful.