Search found 231 matches
- Mon Dec 29, 2014 3:59 pm
- Forum: General Bullet Physics Support and Feedback
- Topic: multiple independent simulations.
- Replies: 1
- Views: 6109
Re: multiple independent simulations.
This section of the forum is for generic physics development, not Bullet-specific. If you haven't already, please post this question in the other section of the forum with regards to Bullet users.
- Thu Oct 02, 2014 3:41 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: Any smart ideas on contact resolution priorities?
- Replies: 8
- Views: 16024
Re: Any smart ideas on contact resolution priorities?
I'm pretty sure they mean to iterate over all of the sorted constraints in one loop.
- Thu Sep 04, 2014 6:18 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: The difference between two constraint method
- Replies: 3
- Views: 7724
Re: The difference between two constraint method
Yes, that can have a significant effect in some cases, for example when stacking boxes. Various people have tried various orders with varying success. As a start, you might search for 'shock propagation' which I think was originally proposed by Guendelman.
- Thu Sep 04, 2014 4:38 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: The difference between two constraint method
- Replies: 3
- Views: 7724
Re: The difference between two constraint method
I think you've highlighted the main advantage of direct solving. One downside, however, is that it is not simple to directly solve certain types of constraints, in particular collision and friction with their limits. So you need an MLCP solver. If this has ever been combined with a sparse matrix sol...
- Wed Aug 27, 2014 8:47 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: How many iteration should be used for collision detection
- Replies: 2
- Views: 5554
Re: How many iteration should be used for collision detectio
Iterative solving is one way to handle multiple constraints that are not independent of each other. It's not clear why it is "obvious" to you that some kinds of collision constraints do not need to be iteratively solved. If it is the only constraint that needs to be solved, or it is comple...
- Wed Aug 20, 2014 6:21 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: Position-based Elastic Rod
- Replies: 10
- Views: 31978
Re: Position-based Elastic Rod
I think a lot of people are still checking this forum, but few are posting new questions.
- Thu Jul 03, 2014 9:49 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: Numerical Method
- Replies: 2
- Views: 6187
Re: Numerical Method
The ODEs are mildly simplified - rotation ignores the gyroscopic/Coreolis effect (whatever it's called). The numerical method is Symplectic Euler. This could be a big discussion, but based on the number of people who have tried different integration schemes, it's likely a waste of your time to try i...
- Thu Apr 17, 2014 6:12 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: GJK/EPA and hollow shapes
- Replies: 2
- Views: 7607
Re: GJK/EPA and hollow shapes
Wouldn't hollow be the same case as concave? In which case, EPA/GJK aren't really suited to the task.
- Mon Mar 24, 2014 4:39 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: Collision & contacts <=?=> LCP
- Replies: 6
- Views: 10431
Re: Collision & contacts <=?=> LCP
Box2D is the first link in this thread, but the whole thread has some good resources to look at:
http://www.bulletphysics.org/Bullet/php ... p?f=6&t=63
http://www.bulletphysics.org/Bullet/php ... p?f=6&t=63
- Mon Mar 24, 2014 4:37 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: Collision & contacts <=?=> LCP
- Replies: 6
- Views: 10431
Re: Collision & contacts <=?=> LCP
A lot of people seem to learn from Box2D by extending it into 3D.
- Mon Mar 17, 2014 6:01 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: Collision & contacts <=?=> LCP
- Replies: 6
- Views: 10431
Re: Collision & contacts <=?=> LCP
If you want to solve for contacts, you need to solve an MLCP (mixed linear complementarity problem).
- Mon Feb 03, 2014 10:22 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: Looking for research topics in areas of realtime physics
- Replies: 10
- Views: 19086
Re: Looking for research topics in areas of realtime physics
My work is more engineering-related, where double-precision is more common. Thanks for the additional info and pointers about this issue, though. Your example mass ratio is much more extreme than anything I use in practice. Originally I thought you were just complaining about the limit of most game ...
- Mon Feb 03, 2014 6:46 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: Looking for research topics in areas of realtime physics
- Replies: 10
- Views: 19086
Re: Looking for research topics in areas of realtime physics
As a motivating example, imagine a mass of 1e5 kg resting on top of a mass of 1e-5 kg resting on top of the floor. What's the force that the smaller body has to deliver to the larger body to keep it from falling down? Basically gravity * 1e5. And then, by Newton's third law, what's the force that t...
- Fri Jan 31, 2014 3:49 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: Looking for research topics in areas of realtime physics
- Replies: 10
- Views: 19086
Re: Looking for research topics in areas of realtime physics
A good way of handling collision response between bodies with vastly different mass ratios would be a reasonable project. It's not that it's an open problem so much as it's an unexplored problem. The onus is usually on the users to make the system less extreme by tweaking the masses. See, eg, this ...
- Thu Jan 30, 2014 4:25 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: Rigid body box stacking
- Replies: 32
- Views: 54681
Re: Rigid body box stacking
In my own simulation this style is very stable, but I have seen Erwin on these forums state that if an object slides quickly along a plane one of the friction axes can converge before the other causing an arced path of travel. I haven't noticed this artifact myself though. Like Dirk and Erwin, I've...