Search found 20 matches

by Baune
Fri Jul 04, 2014 3:05 pm
Forum: General Bullet Physics Support and Feedback
Topic: [JBULLET] Axes on BTGeneric6DofConstraint and lock/unlock ?
Replies: 23
Views: 22698

Re: [JBULLET] Axes on BTGeneric6DofConstraint and lock/unloc

I'm not sure this is exactly what you had in mind but what you said led me in the right direction. Seems like it works now. Thanks to all ! //b1 and b2 are bodies var r1 = b1.getPhysicsRotation().toRotationMatrix() r1 = r1.invert() var r2 = b2.getPhysicsRotation().toRotationMatrix() r2 = r2.invert()...
by Baune
Thu Jul 03, 2014 1:59 am
Forum: General Bullet Physics Support and Feedback
Topic: [JBULLET] Axes on BTGeneric6DofConstraint and lock/unlock ?
Replies: 23
Views: 22698

Re: [JBULLET] Axes on BTGeneric6DofConstraint and lock/unloc

who CAN figure this out ? I spent the better part of an afternoon before I fully grasped how to set up any of the various constraints in the constraint demo. I spent those few hours isolating constraints and changing their setups to understand what was happening. This wiki page helped: http://bulle...
by Baune
Wed Jul 02, 2014 11:46 pm
Forum: General Bullet Physics Support and Feedback
Topic: [JBULLET] Axes on BTGeneric6DofConstraint and lock/unlock ?
Replies: 23
Views: 22698

Re: [JBULLET] Axes on BTGeneric6DofConstraint and lock/unloc

In this excerpt from the Ragdoll class lies the answer, I think, but damn if I understand the logic behind it. transform.setIdentity(); transform.setOrigin(btVector3(btScalar(0.), btScalar(scale_ragdoll*1.2), btScalar(0.))); m_bodies[BODYPART_SPINE] = localCreateRigidBody(btScalar(1.), offset*transf...
by Baune
Wed Jul 02, 2014 11:06 am
Forum: General Bullet Physics Support and Feedback
Topic: [JBULLET] Axes on BTGeneric6DofConstraint and lock/unlock ?
Replies: 23
Views: 22698

Re: [JBULLET] Axes on BTGeneric6DofConstraint and lock/unloc

So we have two axes that, defined local space, must point in the same global direction. Isnt that a recipe for disaster I mean who CAN figure this out ?
But your answer makes sense now I just have to find a way to fix it..
by Baune
Wed Jul 02, 2014 1:35 am
Forum: General Bullet Physics Support and Feedback
Topic: [JBULLET] Axes on BTGeneric6DofConstraint and lock/unlock ?
Replies: 23
Views: 22698

Thanks Basroil, but that doesnt make any difference. I assume the matrices represents the axes directions in local space so a simple identity matrix should do it ?
by Baune
Sat Jun 28, 2014 12:38 pm
Forum: Physics authoring tools, serialization, standards and related topics
Topic: Bullet in blender: capabilities and limitations
Replies: 1
Views: 38652

Re: Bullet in blender: capabilities and limitations

You can write Python scripts in blender and there is a physics API. There is an entire "game engine" in blender-
by Baune
Fri Jun 27, 2014 10:48 pm
Forum: General Bullet Physics Support and Feedback
Topic: [JBULLET] Axes on BTGeneric6DofConstraint and lock/unlock ?
Replies: 23
Views: 22698

Re: Set the axes on BTGeneric6DofConstraint and lock/unlock

OK had time to look at it again. I think I get it but still, there are some strange issues when setting the angular limits. If I rotate the bodyA 30 degrees around the the X axis and set the limit to 0 degrees (or anything less than 30) the joint will align the two bodies. I thought the limit angle ...
by Baune
Tue Jun 24, 2014 5:59 pm
Forum: General Bullet Physics Support and Feedback
Topic: [JBULLET] Axes on BTGeneric6DofConstraint and lock/unlock ?
Replies: 23
Views: 22698

Re: Set the axes on BTGeneric6DofConstraint and lock/unlock

I was very confused when learning constraints as well due to the FrameInA and FrameInB stuff. If you do a forum search there are a few threads that go into detail about them, but really as these other guys have said, the ConstraintDemo is the best place to go to learn. I suggest starting with a hin...
by Baune
Tue Jun 24, 2014 12:10 am
Forum: General Bullet Physics Support and Feedback
Topic: [JBULLET] Axes on BTGeneric6DofConstraint and lock/unlock ?
Replies: 23
Views: 22698

Re: Set the axes on BTGeneric6DofConstraint and lock/unlock

As as I understand it now..if you set the limit of -10,10 degrees on X angular rotation, it means that body a and b X axis cant have a difference more than 10 degrees in their rotation in each direction. When you attach the joint and there is more than that, bullet will compensate by rotating the bo...
by Baune
Mon Jun 23, 2014 4:48 pm
Forum: General Bullet Physics Support and Feedback
Topic: [JBULLET] Axes on BTGeneric6DofConstraint and lock/unlock ?
Replies: 23
Views: 22698

Re: Set the axes on BTGeneric6DofConstraint and lock/unlock

Maybe I will understand you later, right now I dont. Not a single word. im probably dumb...but I need 3 axis, three vectors to define them. And I cant see where they come from.
by Baune
Mon Jun 23, 2014 4:11 pm
Forum: General Bullet Physics Support and Feedback
Topic: [JBULLET] Axes on BTGeneric6DofConstraint and lock/unlock ?
Replies: 23
Views: 22698

Re: Set the axes on BTGeneric6DofConstraint and lock/unlock

Thanks you for that. But what does "frameInA and B represent the local axis location and basis in the reference frame of rigid body rbA and rbB respectively." mean ?
by Baune
Mon Jun 23, 2014 2:53 pm
Forum: General Bullet Physics Support and Feedback
Topic: Local /global coordinates (why always local ?)
Replies: 8
Views: 8539

Re: Local /global coordinates (why always local ?)

Im bad at it as well and I doubt that I will ever be any good. I mostly rely on codesnippets that I dont really understand.
by Baune
Mon Jun 23, 2014 2:24 pm
Forum: General Bullet Physics Support and Feedback
Topic: Local /global coordinates (why always local ?)
Replies: 8
Views: 8539

Re: Local /global coordinates (why always local ?)

I'm pretty much the worst mathematician I know, and I don't have a problem translating between coordinate spaces. But if you think it should be in the library you can always submit a patch. If you have "no problems" then you are better than the average. By a longshot. Because I think the ...
by Baune
Mon Jun 23, 2014 2:18 pm
Forum: General Bullet Physics Support and Feedback
Topic: [JBULLET] Axes on BTGeneric6DofConstraint and lock/unlock ?
Replies: 23
Views: 22698

Re: Set the axes on BTGeneric6DofConstraint and lock/unlock

setAngularLowerLimit/setAngularUpperLimit are for angular motion. If you are talking about linear motion you would use setLinearLowerLimit/setLinearUpperLimit. And yes, setting all limits to btVector3(0,0,0) would completely lock motion. You can really learn a lot by playing with the constraint dem...