Real-Time Physics Simulation Forum

Hello everyone,

Still a beginner in Bullet. I need to check if different parts of a UR5 robot collide on each other, giving its different joints positions.
I first loaded the STL files of the different joints of the robot, and created GImpact shapes from it.
I use a demo called "FeedbackCollision" for having a classic collision detection.

It works well when I drop a GImpact body (for example, joint No. 1) on a BoxShape (called the floor), I can even say which triangles of the joint collided with the floor.
But two GImpact bodies just act like ghosts to each other.
I read internet pages during two days, didn't find solution. Can someone help me ?

Thanks a lot !

Did you register the GIMPACT collision algorithm?

erbisme4@yahoo.com wrote:Did you register the GIMPACT collision algorithm?

Code: Select all

btCollisionDispatcher * dispatcher = static_cast<btCollisionDispatcher *>(m_pDynamicsWorld->getDispatcher());
btGImpactCollisionAlgorithm::registerAlgorithm(dispatcher);

I had not... Thank you so much !

Let me know how that goes for you. I had some pretty awful experiences with GImpact shapes, where they would get sucked into each other when near, as well as penetration issues.

erbisme4@yahoo.com wrote:Let me know how that goes for you. I had some pretty awful experiences with GImpact shapes, where they would get sucked into each other when near, as well as penetration issues.

Hum, OK. As far the collision detection between two of them seems to work. But yes, it looks like it works only in special condition : when they are already in a motion state that makes them collide (because this is what I need for my application).
For now, I'm just trying to build the UR5 robot joint by joint with 7 GImpact shapes, and then will run the same collision detection. Keep you in touch.