Weapons

#1 I belive NOT. There is almost never a need for them to have collision with anything.

#2 Accept if you want to be able to pick them up from off the ground, you NEED a collision mesh.

#3 The common way of mounting a weapon onto a character is using an Image, in which you would call mountImage, instead of mountShape. The world weapons that you pick up DO need a collision mesh, but the actual Images don't require it.

The only tricky thing I can think of is when you run into a wall and your weapon is being held so far away from the body (like a shotgun or sniper rifle), that it goes into the wall. This never looks good. . .

#4 I think by default the type of object used for a pickup doesn't need a collision mesh, the code for the object takes over; if I remember and it is correct...I am pretty sure if you want them reacting to projectiles, a LOScol mesh is needed.

@Michael P: there is a node you can add to an object that helps with this quirk, I think. Read up on retractionPoint and you may find out more.

Yes, I agree; being able to sticky your weapon into a wall and fire is not good. Neither is watching it slide up your arms...

#5 Collisions on weapons might also be useful when you don't want sun flares passing through them.