Real-Time Physics Simulation Forum

Then you definitely want to look at this article about loading a .bullet file ;) http://bulletphysics.org/mediawiki-1.5.8/index.php/Bullet_binary_serialization I'm actually having exactly the same concerns and did it as proposed in the article. Works fine except a scale problem that have to see with...

Hi, I got exactly the same issue... Did you get any hint on it ? Reading the wiki post you linked, I think the problem is that it's actually not 'interpolating' values as it says, but 'extrapolating' values. And I think the problem is that it's wrongly extrapolated, and when it's computed during the...

Doesn't seems like an SDK issue.
Are you talking about Dynamica ?

I already explained the erp and cfm parameters in this post : http://bulletphysics.org/Bullet/phpBB3/viewtopic.php?f=9&t=6792 and this post: http://bulletphysics.org/Bullet/phpBB3/viewtopic.php?f=9&t=7533 But in short: If CFM is set to zero, the constraint will be hard. If CFM is set to a po...

Maybe I'm out of subject, but isn't it a problem that should better be solved by using a prismatic joint ensuring the train will stay on the rails ?

I dunno about 'split', but here is about cfm (constraint force mixing) and erp(error reduction parameter): If CFM is set to zero (which is the default value), the constraint will be hard. If CFM is set to a positive value, it will be possible to violate the constraint by "pushing on it" (f...

Bigpet wrote: otherwise the value won't change as long as DISABLE_DEACTIVATION is set.

I thought that was the point

You can configure your rigid body to never deactivate by adding a flag like this: Just do it on bodies when you activate the motors, and undo it when you deactivate the motors like this:

Well, then you still could inherit from the btRigidBody, using default values for the construction, and changing them later using the protected btRigidBody::setupRigidBody method. I never tried it, but you should give it a try... Would looks like: Terrain::Terrain(Game* p_Game) : btRigidBody(/*put d...

One way to keep track of which rigid body belongs to which object would be to have a std::map<btRigidBody*, CObject*> in your collision/physics class where you can simply access any object by using a rigid bodys pointer. You'r familiar with maps, aren't you? That would be my suggestion too As an al...

You can change the "force" that bullet can use to correct the error on a constraint. There are 2 parameters for that, called error reduction parameter (ERP) and constraint force mixing (CFM). If you want to get more information on each, here is an article that explains it quite well (sorry...

Dr.Shepherd wrote: Anyone could tell me why it is set up in this way?

I guess that would be because the glut callback needs a C style function callback while the ClientMoveAndDisplay is the method of a class and can't be directly used by Glut.

Depends what you want to do exactly ;) Your object may be working in kinematic mode only (which mean physic will have no effect on the object, but the object may have effects on other physic objects). In this case, your have to initialize it as a kinematic object: _dynamicRigidBody->setCollisionFlag...

thx, dunno how I could have missed it

I'd like to disable some collision pairs in my bullet simulation. I used to have constraints between some of my bodies, so it was easy to disable collisions between them. Now I would like to disable collision detection between these bodies, but with no constraints between them. Is there an easy way ...