$concave not creating my hole?

Ive got a model that ive made the collision mesh for: http://prntscr.com/9xhd5d

And this is how the collision model keeps showing up: http://prntscr.com/9xgmd0

Can someone please tell me why this is happening? Im creating the mesh using Cinema 4D, exporting as OBJ into milkshape, exporting from there as SMD and into StudioMDL. Ive spent hours trying to find the solution and yet i still cannot find anything

This is my QC:

$modelname "models/speeder.mdl"
$cdmaterials "models/speeder"

$scale 1.0
$surfaceprop "Metal"

$body "Body" "speeder.smd"

$sequence "idle" "speeder.smd" fps 30

$collisionmodel "speeder_collision.smd"
$mass 1200
$maxconvexpieces 100

The entire mesh was made using primitive shapes as told in the https://developer.valvesoftware.com/wiki/Collision_mesh under Cinema 4D and still this bastard of a compiler does my mesh shittly. I have used the worm wall for 3DS Max and that just creates the CM like it does in the model viewer screenshot.

each of the elements of the collision mesh actually have to be convex. $concave means they won’t get merged together into one.

Plus it looks like the collision model isn’t rigged to anything.

Actually they don’t, they just have to be sealed elements sharing a smoothing group, then the compiler will make them convex via shrinkwrapping.

Well yeah. But if you’re planning to make something concave, you generally have to build it out of discrete convex elements.

Ah yeah thanks, i managed to fix it by having to use seperate objects. I tried cheating my way out of making a collision model and it seems that theres no easy way!

If you have max, but it should apply to nearly all editors.