Search found 235 matches

by bone
Mon Mar 07, 2016 6:27 pm
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: Implementing hinge constraint
Replies: 11
Views: 10060

Re: Implementing hinge constraint

The Jacobians are simply a and b for the first body (and, of course, -a, and -b for the second body). Is this the result you are getting?
by bone
Tue Feb 23, 2016 1:50 pm
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: Correcting angular velocities in an angular constraint
Replies: 2
Views: 3579

Re: Correcting angular velocities in an angular constraint

I'm probably not fully considering your problem, but is there a solution where you can temporarily convert the quaternions to a rotation around an axis? (I'm talking about either the 4-component "axis and angle" or the similar 3-component "axis rotation" which is simply the unit axis multiplied by t...
by bone
Thu Feb 04, 2016 3:46 pm
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: [SOLVED] Position Based Elastic Rods implementation
Replies: 32
Views: 20919

Re: [SOLVED] Position Based Elastic Rods implementation

Glad I was of some minor help!

I look forward to checking out the implementation (someday, at least - it's not pertinent to my current project but I'd like to fiddle around with it in the near future).
by bone
Mon Feb 01, 2016 4:05 pm
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: [SOLVED] Position Based Elastic Rods implementation
Replies: 32
Views: 20919

Re: [SOLVED] Position Based Elastic Rods implementation

I had tried out Korzen's original demo and also experienced that wiggle exactly once. I couldn't figure out how to reproduce it so I never mentioned it. IIRC, the paper detailed a specific order of solving the constraints ... did you follow that?
by bone
Tue Jan 12, 2016 2:41 pm
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: [SOLVED] Position Based Elastic Rods implementation
Replies: 32
Views: 20919

Re: [SOLVED] Position Based Elastic Rods implementation

Just a tip you could also replace the need for this array altogether by doing something like this in ComputeDarbouxVector function. <snip> const int i = c; const int j = (c+1) % 3; const int k = (c+2) % 3; </snip> Are you trying to make it cleaner or faster? If the performance of that code is criti...
by bone
Wed Jan 06, 2016 5:14 pm
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: [SOLVED] Position Based Elastic Rods implementation
Replies: 32
Views: 20919

Re: Position Based Elastic Rods implementation

I haven't looked, but it's possible that Jan Bender's PBD code has an implementation, too. But no matter since you've apparently found a solution.
by bone
Wed Dec 30, 2015 4:20 pm
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: deleted post.
Replies: 2
Views: 3826

Re: Can I get a collided triangle by using Bullet?

You might note that this section of the forum specifically notes that you don't post Bullet support questions here. Please try another section.
by bone
Wed Dec 09, 2015 2:41 pm
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: Collision response - solver, penetration recovery
Replies: 21
Views: 12421

Re: Collision response - solver, penetration recovery

OK, you're (basically) right, ERP is a form of Baumgarte stabilization. My confusion stems from originally using Baumgarte's method on a force-based rather than impulse-based physics system. Perhaps that even has something to do with my difficulty tuning it, but that's water over the dam at this poi...
by bone
Fri Dec 04, 2015 3:38 pm
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: Collision response - solver, penetration recovery
Replies: 21
Views: 12421

Re: Collision response - solver, penetration recovery

There is more than one way to fix the inevitable overlap. I don't think Baumgarte stabilization is in favor anymore (I have used it in the past, but it seemed difficult to tune). If you look up the CFM/ERP variables that Erin Catto uses on his impulses, that is one good method (which I am currently ...
by bone
Mon Sep 21, 2015 8:39 pm
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: F-Zero physics
Replies: 1
Views: 3136

Re: F-Zero physics

Presumably your 'car' needs some downforce, but not generated from aerodynamics like a real car, otherwise you'd probably float off at zero speed. Make sure normal gravity is off (which is a force vector relative to the world), and then apply some sort of replacement force vector always pushing your...
by bone
Thu Aug 20, 2015 4:12 pm
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: PGS accumulating impulses vs applying each step
Replies: 7
Views: 6294

Re: PGS accumulating impulses vs applying each step

Well, it probably needs to accumulate the impulse for other purposes (limits, warmstarting, constraint breakage, debugging, etc.). But I personally don't know how a PGS solver could work without updated velocities each iteration.
by bone
Thu Aug 20, 2015 2:01 pm
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: PGS accumulating impulses vs applying each step
Replies: 7
Views: 6294

Re: PGS accumulating impulses vs applying each step

For the subsequent iterations to actually do something useful, I think the velocity has to be updated and stored somewhere . But it's possible that it is not being stored in the rigid body object itself. Are you sure that the velocity isn't being copied somewhere before the first iteration (for exam...
by bone
Tue May 05, 2015 2:20 pm
Forum: Links, Papers, Libraries, Demos, Movies, Comparisons
Topic: Interaction with Geometry video now public on GDC Vault
Replies: 3
Views: 6206

Re: Interaction with Geometry video now public on GDC Vault

Thanks Mr. Melax for the talk and thanks RBD for the links!
by bone
Mon Apr 06, 2015 10:24 pm
Forum: Links, Papers, Libraries, Demos, Movies, Comparisons
Topic: My 2015 links
Replies: 3
Views: 5918

Re: My 2015 links

Interesting papers, thanks for the ideas!