Collision model help

[Ghostlier]

I'm trying to compile a model for a map I'm working on, but the collision model breaks on-compile.

[t]http://puu.sh/qjyuF/28541a5d38.jpg[/t]

Here's the model with the collision model's outline over the model as a new layer as seen in Blender. This is how the collision model [i]should[/i] work.

[t]http://puu.sh/qjyw6/fa0258438a.png[/t]

The collision model, after everything's compiled, cuts across like this. I was talking to someone about it and it seems like it [i]could[/i] be StudioMDL compiling the collision model automatically because the one I supplied has too high of a poly count, but it happens even when there's an incredibly small vertex count.

$modelname "props/stairs1.mdl"
$surfaceprop rock
$scale 256
$staticprop
$cdmaterials "props/tower/floor3"

$body root "stairs.smd"
$sequence idle "stairs.smd"
$collisionmodel "stairs_collision.smd" { $concave }

Here's the QC file, and [url=http://puu.sh/qjz72/c5981750e2.zip]here's the two SMD files if anybody feels like looking into it.[/url]

I have no idea what's going on with it, so I'm wondering how to fix it, or would it be better to create a series of nodraw brushes to create the shape?

[Portugalotaku]

Source collision models must always be convex. The only way to have a concave collision model is by having it being made of several separate models.
Cut that model up into pieces, give them all the same smoothing group and it should work.

[Ghostlier]

I'm afraid I'm still a bit confused at what I should be doing.

I have the collision model split into 3 separate meshes:

[t]http://puu.sh/qk6Vi/85a0e88317.png[/t]

(not aligned for the sake of the screenshot)

..but from there I'm lost.

[Portugalotaku]

Give them all the same smoothing group and compile.

[episoder]

screen looks good. very simple. you should close the open ends of the box meshes tho. it gotta be completely closed concave boxes/volumes/surfaces.

[Portugalotaku]

[QUOTE=episoder;50802767]screen looks good. very simple. you should close the open ends of the box meshes tho. it gotta be completely closed concave boxes/volumes/surfaces.[/QUOTE]

He said it was not aligned for the sake of a screenshot.

[episoder]

[QUOTE=Portugalotaku;50803216]He said it was not aligned for the sake of a screenshot.[/QUOTE]

okay. i've seen that. he spread the seperate collision meshes. but the ends of those gotta be closed. or not?!?

[Ghostlier]

Well, I ended up getting it working.

Not sure if closing each separate mesh was a requirement, but I did it anyways. I joined the meshes together and then applied the smooth shading onto the whole set, and now it seems to export correctly.

Thanks a lot guys!

[Stiffy360]

Basically, you don't need separate meshes, but separate sealed fully smooth elements.

And they can be any shape, the compiler will make them convex.

Basically you could dupe your mesh, split it up, seal all holes, smooth everything, and export it.