Help! Problems making a collision model

[VelvetFistIronGlove]

I've made a cannon model in XSI for cp_siege, and am trying to make a physics model for it, as the one generated by default is pretty poor. So I made a model out of six cubes:


However, after exporting that, when I compile the model I get a whole lot of errors:

Building binary model files...
Working on "vfig-cannon.qc"
SMD MODEL ./vfig-cannon_ref.smd
SMD MODEL ./vfig-cannon_idle.smd
SMD MODEL ./vfig-cannon_phys.smd
WARNING: Model has 2-dimensional geometry (less than 0.500 inches thick on any axis)!!!
WARNING: Model has 2-dimensional geometry (less than 0.500 inches thick on any axis)!!!
WARNING: Model has 2-dimensional geometry (less than 0.500 inches thick on any axis)!!!
WARNING: COSTLY COLLISION MODEL!!!! (36 parts - 20 allowed)
WARNING: Error with convex elements of ./vfig-cannon_phys.smd, building single convex!!!!
Model has 1 convex sub-parts
Collision model completed.

And then it clearly generated an incorrect physics model:


Has anyone worked with physics models before? Any ideas why this physics model is not compiling correctly?

 

[Snipergen]

Well, I'm following this thread too... because I'm still not sure how to make a great collision model.

Has to be concave I think. And it says something about too close on Y axis...? Check some edges that are too close to eachother maybe.. I don't know

Shmitz help us out here will ya

 

[VelvetFistIronGlove]

Turns out the error messages I was getting were due to bad unwrapping -- I think I had multiple sets of UV coordinates on the same boxes.

And thanks to Buddikaman (Come post in this thread so I can use the Thanks button on you!) I found out that the separate boxes in the physmodel each have to have their own smoothing group, or the model compiler will just use the convex hull of the lot. I completely missed seeing this awesome tut about making models here on the forums, so I'll post the link for everyone: Complete Guide to Adding Custom Objects to your TF2 Map

 

[VelvetFistIronGlove]

All sorted now:

 

[kimangroo]

I completely missed seeing this awesome tut about making models here on the forums, so I'll post the link for everyone: Complete Guide to Adding Custom Objects to your TF2 Map

lol when I read your post, I knew I had recently read an excellent tut all about collision models n stuff which would probably help with your question. I tried to find it via google for about 20 mins, but all i could remember was that the prop being made was a sofa. Didn't realise it was on this site!

BTW love the cannon and the moving porticulis in your map too.

 

[Hawk]

Wow, the cannon turned out looking really nice.

And it's funny, more than half the time I do a google search of my mapping problems, it takes me to this site. I feel like we've become the best TF2 mapping site.