Bullet Physics: Rigidbody collision enabled, physics disabled

Question

I have a rigidbody with the correct physics and collision functionalities. However, I want to make this object "invisible" so it is not considered in the physics (stepsimulation) but still generates the right collisions. Of course I can just not render it in my 3D scene but I somehow also need to make it "invisible" for the physics simulation so another objects can go through it. Does anyone has a suggestion how to do this? I guess this should just be a setting but until now I could not find it.

So in short, I still want the object to raise the right collision signals so I know when another object collides with it / walks through it. But I would like that other objects can walk through it instead of bouncing of this object.

Answer 1

Have a look at btGhostObject, which is a physics object not affected by physics while still being able to detect collisions:

http://bulletphysics.org/Bullet/BulletFull/classbtGhostObject.html#details

It's usually used for triggers or character movement as you can read inside the link.

Small tutorial: http://www.bulletphysics.org/Bullet/phpBB3/viewtopic.php?f=9&t=7468