Non-colliding rigid bodies

[Leonardo]

My question is fair simple. How do I make rigidbodies that don't collide at all? i want to apply force and other things related to rigidbodies but I want them to totally ignore collisions. How can I do such thing?

EDIT: shortly after I wrote this post, I found a btEmptyShape - would that be the answer?

Thanks.

[Mako_energy02]

No, using the shape will cause there to be an overflow in the objects AABB calculation, and then bullet will remove it from the simulation. At least...thats what happened the last time I tried it. You want to look at collision flags on the btCollisionObject base class:

http://bulletphysics.com/Bullet/BulletF ... bject.html

Look at the enums near the top, in particular "CF_NO_CONTACT_RESPONSE". Get the existing flags and add that flag to it, and then pass it in to "SetCollisionFlags(int)". Should look something like this(taken from my trigger object code):

Code: Select all

Ghost->setCollisionFlags(Ghost->getCollisionFlags() | btCollisionObject::CF_NO_CONTACT_RESPONSE);

In some cases people have reported that not having any effect, which I'm not sure what that is about...I've never had issues. Good luck.

[Leonardo]

I will try that. Thank you.