Search found 231 matches
- Thu Jan 16, 2014 4:00 pm
- Forum: Career Opportunities
- Topic: Physics/animation engineer position @ NaturalMotion
- Replies: 8
- Views: 63800
Re: Physics/animation engineer position @ NaturalMotion
I would recommend using the links in the first post to contact them directly, I doubt they are monitoring this forum post.
- Wed Nov 13, 2013 3:50 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: long stick behaviour in the air
- Replies: 5
- Views: 10429
Re: long stick behaviour in the air
http://math.ucsd.edu/~sbuss/ResearchWeb ... 11Talk.pdf
That might help if you need more accurate methods. Sam Buss has an older paper somewhere if you want more explanation.
That might help if you need more accurate methods. Sam Buss has an older paper somewhere if you want more explanation.
- Mon Nov 04, 2013 6:05 pm
- Forum: Links, Papers, Libraries, Demos, Movies, Comparisons
- Topic: rigid body Rubik's Cube short video
- Replies: 2
- Views: 40521
Re: rigid body Rubik's Cube short video
Heh, nice one - thumb's up!
- Tue Oct 01, 2013 4:46 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: Is semi-implicit Euler unconditionally stable?
- Replies: 3
- Views: 10357
Re: Is semi-implicit Euler unconditionally stable?
It depends on what you're simulating. For a simple mass-spring system, there is a simple formula for whether it is too stiff for semi-implicit Euler to be stable. IIRC, the oscillation frequency has to be less than half of the physics sampling frequency.
- Thu Aug 15, 2013 2:38 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: Tank track simulation?
- Replies: 4
- Views: 13194
Re: Tank track simulation?
Good point, I agree cylinders might work pretty well.
- Wed Aug 14, 2013 6:37 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: Tank track simulation?
- Replies: 4
- Views: 13194
Re: Tank track simulation?
Not to be nitpicky, but I think you want the word "stretched" not "sketched" - I'm just mentioning this because it took me a moment to figure out what you were saying. Anyway, that's a challenging problem to do well in realtime. I think you'll definitely have to customize your so...
- Fri Aug 02, 2013 1:50 pm
- Forum: General Bullet Physics Support and Feedback
- Topic: how to using bullet in serverEndï¼
- Replies: 3
- Views: 3756
Re: how to using bullet in serverEnd?
Try your question in the "General Bullet Physics ..." area, you'll probably get a better response.
- Tue Jul 23, 2013 7:17 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: SI & double-pendulum: motion getting damped
- Replies: 10
- Views: 17538
Re: SI & double-pendulum: motion getting damped
if you're changing the velocity directly with an impulse, you're changing the energy level. And if it's "stabilizing", it's going to be towards less energy. Reasonable enough and maybe this is what happens in practice with SI but the underlying theoretical principle (if I understand it co...
- Tue Jul 16, 2013 8:30 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: SI & double-pendulum: motion getting damped
- Replies: 10
- Views: 17538
Re: SI & double-pendulum: motion getting damped
BTW, I'm not presuming to be sure that's the *only* cause of damping. I'm just not currently aware of anything else that necessarily causes it. For example, SI may also be inadvertently causing it, simply by converging from one side of the "correct" solution.
- Tue Jul 16, 2013 6:02 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: SI & double-pendulum: motion getting damped
- Replies: 10
- Views: 17538
Re: SI & double-pendulum: motion getting damped
Good point: my implementation of Baumgarte *is* in a system using force-level acceleration, so the damping is indeed more obvious. I'm not sure it matters that much: if you're changing the velocity directly with an impulse, you're changing the energy level. And if it's "stabilizing", it's ...
- Tue Jul 16, 2013 3:04 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: SI & double-pendulum: motion getting damped
- Replies: 10
- Views: 17538
Re: SI & double-pendulum: motion getting damped
I think an answer to the second question may help with the first. Yes, the predicted velocities already handle external forces, but the main problem is that the direction of the constraint (the angle of the pendulum itself) is changing during the timestep, and that's not accounted for in most modern...
- Mon Jul 15, 2013 2:56 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: SI & double-pendulum: motion getting damped
- Replies: 10
- Views: 17538
Re: SI & double-pendulum: motion getting damped
I think you'll find even a 'single' pendulum will get damped, because the constraint solver doesn't solve this exactly over the entire timestep, it only solves it exactly at the beginning of the timestep (at least with symplectic Euler integration, but IIRC there exists no integration scheme that wi...
- Tue May 14, 2013 4:20 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: PGS Iteration: local vs. global
- Replies: 13
- Views: 17706
Re: PGS Iteration: local vs. global
I'm not sure what other people do, but I just consider a single collision as a constraint, to be solved generically along with every other constraint. I suppose that's closer to your global solution.
- Mon May 13, 2013 5:13 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: Chris Hecker's impulse calculation versus block solver
- Replies: 10
- Views: 15947
Re: Chris Hecker's impulse calculation versus block solver
Ahh, okay, thanks. I misunderstood.
- Fri May 10, 2013 6:05 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: Chris Hecker's impulse calculation versus block solver
- Replies: 10
- Views: 15947
Re: Chris Hecker's impulse calculation versus block solver
Sorry, which equation number of Hecker's is wrong? Thanks.