HingeConstraint constructor bug

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Erwin Coumans
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Re: HingeConstraint constructor bug

Post by Erwin Coumans » Tue Apr 08, 2008 1:08 pm

Hi Dragonlord,

Can you reproduce this issue with hinge limits in a Bullet ConstraintDemo?

Can you try out the new btSliderConstraint in Bullet 2.68 beta? It can be configured as a limited hinge, see the SliderConstraintDemo.


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Re: HingeConstraint constructor bug

Post by Dragonlord » Tue Apr 08, 2008 5:32 pm

I'm giving some more editing to my editor first so I can try also work on multiple constraints ( currently I hacked in the test constraint on loading ). Should not take more than a day or two. I'm then going to test the different constraints and maybe ( if I find some desktop-recorder for Linux which is worth it and can record from direct-rendering displays ) I can give some videos show better what happens with the constraint.

EDIT: Added some visual joint error display and fiddled a bit around. Not sure yet what to make of it. One thing is though for sure the large errors happen due to certain placement of the constraints. Maybe the problem with the door has not been just due to the hinge constraint. I find also cases where the point-socket constraint errors like hell but in contrast to the hinge constraint the errors in the ball-socket constraint have a smooth curve. Hence the ball-end moves out of place to the socket in a smooth curve not jittering hiding the incorrect behavior whereas the hinge constraint has ( which I consider astonishing ) smaller maximum error in the joint but weasels around the correct position erratically. In fact it's this erratic motion which gives the hinge constraint the jittery look although it would have less maximum error.

I'm going to play more with the parameters. I'm pretty sure these cause the problem.

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