Search found 7 matches

by info128
Mon Sep 23, 2013 7:37 pm
Forum: General Bullet Physics Support and Feedback
Topic: Alternative to btGeneric6DofConstraint For Ragdolls
Replies: 2
Views: 2720

Re: Alternative to btGeneric6DofConstraint For Ragdolls

I posted a question about this back in 2012 when trying to solve a similar problem ( 6DOF Constraint: Y-axis angular limit > 90 degrees? ). Global quaternion-based constraints would allow for very interesting, complex rigging systems in ragdolls or partially animated, partially simulated skeletal sy...
by info128
Thu Sep 20, 2012 8:38 pm
Forum: General Bullet Physics Support and Feedback
Topic: Generic6DofConstraint z-axis Rotational Motor don't work.
Replies: 2
Views: 2529

Re: Generic6DofConstraint z-axis Rotational Motor don't work

What values are you specifying when calling setAngularLowerLimit()? I ran into a problem using btGeneric6DofConstraint when attempting to make constraint-controlled ragdoll, later realizing that the 6DOF constraint is limited to a hemisphere of motion. The Y-axis only allows +/-90 degrees of rotatio...
by info128
Tue Aug 28, 2012 12:28 am
Forum: General Bullet Physics Support and Feedback
Topic: [SOLVED] btGeneric6DofConstraint: Limit in motor (1). Bug?
Replies: 2
Views: 2473

Re: [SOLVED] btGeneric6DofConstraint: Limit in motor (1). Bu

Just saw your post; I ran into this limitation back in May when attempting to implement a "motor-driven ragdoll" system. This just will not function due to the +/-90 degree limit in the y axis. The solution, it seems, would be to implement a quaternion-based 3DOF or 6DOF constraint. See my...
by info128
Fri Jun 01, 2012 9:02 pm
Forum: General Bullet Physics Support and Feedback
Topic: 6DOF Constraint: Constrained Rigid Body velocity always zero
Replies: 0
Views: 3034

6DOF Constraint: Constrained Rigid Body velocity always zero

I've run into a problem using the linear limit functionality of the 6DOF constraint. In testing, set up a 6DOF constraint between one dynamic rigid body and the world (no second rigid body). Each frame, I call setLinearLowerLimit and setLinearUpperLimit with the same vector, which is an animated poi...
by info128
Thu May 31, 2012 6:44 am
Forum: General Bullet Physics Support and Feedback
Topic: 6DOF Constraint: Y-axis angular limit > 90 degrees?
Replies: 7
Views: 16715

Re: 6DOF Constraint: Y-axis angular limit > 90 degrees?

Thanks for your response - yes, the main problem seems to be that the constraint solver uses Euler angles, and in order to avoid orthogonality problems, one axis must always be limited to +-90 degrees (as you noted). Unfortunately, in my case your proposed solution will not work. As far as I have re...
by info128
Sat May 26, 2012 12:34 am
Forum: General Bullet Physics Support and Feedback
Topic: 6DOF Constraint: Y-axis angular limit > 90 degrees?
Replies: 7
Views: 16715

6DOF Constraint: Y-axis angular limit > 90 degrees?

I've been putting together a skeletal animation/dynamics system using two identical skeletons. One skeleton's joints are keyed/animated. Each of the second skeleton's bones (section between each joint) are set up as a rigid body with a btGeneric6DofConstraint between each rigid body pair. Each frame...
by info128
Thu Mar 03, 2011 3:04 am
Forum: General Bullet Physics Support and Feedback
Topic: Is it just me, is this in slow motion or are things big?
Replies: 2
Views: 2309

Re: Is it just me, is this in slow motion or are things big?

I'm fairly new to Bullet, and just starting to experiment. I did a bit of research into this subject, as the documentation recommends objects should not be much smaller than 10cm or so. This presents a problem for what I would assume to be the majority of physics simulations in games, which require ...