How can i detect which Objects (ID's) collide in Bullet??

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dwells254lb43
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Joined: Wed Jan 21, 2009 12:27 am

How can i detect which Objects (ID's) collide in Bullet??

Post by dwells254lb43 » Tue Jul 14, 2009 11:01 pm

Hello i have been using bullet for a decent amount of time now and i am currently wondering how i can detect which Objects / ID's collide. After a collision occured i want something simple to happen like it take damage etc. But i dont know which functions to call in order to check if a collision has occured, and how to manipulate the collided objects.

I have looked into the collision callbacks on : http://www.continuousphysics.com/mediaw ... d_Triggers

But i dont really understand the code to well, if anyone can help me i will appreciate it ^.^

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Erwin Coumans
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Re: How can i detect which Objects (ID's) collide in Bullet??

Post by Erwin Coumans » Tue Jul 14, 2009 11:57 pm

The wiki link you provide tells that the best way to check for collisions between objects is
to iterate over all contact manifolds, and check if there are at least 1 contact point.

Have you tried that?
Thanks,
Erwin

dwells254lb43
Posts: 10
Joined: Wed Jan 21, 2009 12:27 am

Re: How can i detect which Objects (ID's) collide in Bullet??

Post by dwells254lb43 » Fri Jul 17, 2009 12:03 am

Yes i understood that it iterated through every object and then when it finds a point of collision it will do the code below, however how do i get the ID's of those bodies? Do i use the void pointer? I noticed there was a void pointer in there and i was thinkin i could set it up to return the Id's of the objects that collide, but i was just wondering is there another way?

thloh85
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Re: How can i detect which Objects (ID's) collide in Bullet??

Post by thloh85 » Wed Jul 22, 2009 2:01 am

There is a function called setUserPointer in btRigidBody(or somewhere if it's not there, I couldn't recall) AFAIK, therefore, use setUserPointer with whatever that identifies your body, and getUserPointer to check them.

Hope this helps

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