Real-Time Physics Simulation Forum

I've created a google issue and attached a patch file: http://code.google.com/p/bullet/issues/detail?id=219. As for what's missing in the non-obsolete constraints: - btConeTwistConstraint: motor, soft limits, and damping are all missing. More generally, are soft limits supported by the new solver ar...

Hi, I just updated to the most recent source (it had been a while) and noticed some minor bugs in the obsolete versions of btHingeConstraint and btConeTwistConstraint. Specifically: neither of them reset m_accMotorImpulse. (it accumulates the applied motor impulse per tick, used for impulse clipping...

Hi Roman, I've submitted a patch file to the issue tracker: http://code.google.com/p/bullet/issues/detail?id=180 And thanks for the reference Marcus. I wish I had time to look into it, but time is super tight at the moment. (Barely enough to submit the patch!) So in the meantime, any comments on the...

Hi, I've been working on the ConeTwist constraint lately, and have some additions and fixes I'd like to submit. Additions: - I've added motorization. (only to the "obsolete" solver version so far.) - I've added damping. (ditto) - I've reworked the limit softness. (ditto) Fixes: - More accu...

Hi Erwin, Thanks for your response. Yes, it's just an API inconvenience. (At first I thought it was a "real" problem, but setting mass=0 solves it.) So I'll work around it. But I think that it would be an improvement (possibly for 3.x) to remove the zero-mass-dependency for kinematic bodie...

Hi Erwin, I have a few modifications to btRigidBody and CcdPhysicsDemo that can show what I'm referring to. But so as to not "waste" both our time, I'd like to check something with you first: Is the zero-mass requirement for kinematic bodies really necessary? This strikes me as odd API-wis...

Hmmmm.... that corebonetransform in the constructor looks fishy. (Based on the comment "the default transform of the bone according to cal3D".) What you want here is the transform to the constraint from the bone's origin (in the bone's space). However, the first thing I would check is what...

Hi Blairvoyant,

That did it, it's working on my machine now.
Cool demo!
As for what the problem is... it's hard to say just from the results. (Although, are you really representing individual fingers as bodies? If so, wow.)

Cheers,
Eddy

Hi Blairvoyant,

I tried downloading and running your app, but... "The application failed to initialize properly (0xc0150002)..."
Any ideas? Perhaps due to my glut version (3.7.6)?

Cheers,
Eddy

Let's concentrate on the 2nd issue. I have bodies that regularly switch back and forth between kinematic and dynamic, do I really need to change the mass around each time? Isn't that what the KINEMATIC/STATIC flags are for? As for repro, I'll put a simple one together, but if you look at any constra...

Hi, I've been having several issues lately regarding kinematic bodies. 1. Minor (continuation of this thread): The fact that setting a kinematic body's velocity doesn't work (ie. gets overriden by the motion state, even if we aren't using one) is rather unpleasant, since it means having two differen...

There's an example of how to set a target angle in MotorDemo.cpp. See enableAngularMotor(...) and the code just above it.
(Though I agree it would be nice to provide this as a service in the constraint class.)

Cheers,
Eddy

Hi Youne, I wrote the MotorDemo, but didn't create the hinge constraint (nor the enableAngularMotor method in it). My impression is that the motor tries to achieve the passed velocity, given its settings for max impulse (muscle strength in the demo). Obviously, if the impulse required exceeds the li...

While we're on the subject of kinematic bodies, anyone know what the recommended/safe way is to switch a body between dynamic and kinematic/static mode?

Thanks,
Eddy

I'm still interested in this as well.

Cheers,
Eddy

PS. Bruce, for more info (and links to source), check this topic: http://www.bulletphysics.com/Bullet/php ... hilit=nima