Model behaves as a box

Let's suppose I have a mesh like this:
______________________________
./\......................................................../\
|_|___________________________|_|

(Ignore the dots, the forum doesn't allow me to write multiple spaces)
So, if I drop a ball on this model, when it hits the (imaginary) red line, it stops, like if the mesh was a box, while it should keep falling until the black __ line.
I already tried with Convex and Tree..
It works if I don't use bevel on the top of the "towers.."

hi,

for debug collisions i use OgreNewt::Debugger::showLines(mWorld);
then you can see if it is a box.
so i found my problems in the past...

mfg
goldman82

As you can see for yourself, the model isn't actually convex, so clearly any convex hull will be an approximation, in this case a box.

Tree collisions are quite special though, and there are some intricacies to using them, I recommend you read the documentation very well.

Edit: Oh and I second the debugLines advice. You should really look at how it works and use it, it's very useful.