Collision problem

[DustyDead]

Simply question how to export Blender model to phys mesh?
I saved collision model like metal_gate_phys.smd and in Blender it look like this

But in model viewer it look like this

How to fix this?

Solved
I just forgot to use $concave

$collisionmodel "metal_gate_phys.smd"
{
	$concave
}