Search found 231 matches
- Thu Apr 18, 2013 1:35 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: A verlet based approach for... 3D physics?
- Replies: 6
- Views: 10886
Re: A verlet based approach for... 3D physics?
Indeed, that's going to be more difficult. Particularly the edge/edge case (when an edge of one cube touches the edge of another cube, yet no verts have penetrated the faces of the other cube). I believe some people just skip that case altogether.
- Tue Apr 16, 2013 5:21 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: A verlet based approach for... 3D physics?
- Replies: 6
- Views: 10886
Re: A verlet based approach for... 3D physics?
My previous post should have said "connected" not "converted". Anyway ... Your original post said: "it seems that edges code doesnt work for by cube." I'm asking what isn't working. Does the cube collapse? Blow up? In other words, in what way does it not work? I'm guess...
- Mon Apr 15, 2013 9:37 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: A verlet based approach for... 3D physics?
- Replies: 6
- Views: 10886
Re: A verlet based approach for... 3D physics?
I can't figure out where you're coming up with 18 edges. If every vert in the cube is converted to every other, it should be 28, no? What's not working for you?
- Tue Apr 09, 2013 5:50 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: Rope physics with position constraints question
- Replies: 4
- Views: 14668
Re: Rope physics with position constraints question
If it looks good and the CPU usage isn't causing any problems, I'd say you are done. That being said, yes this could be solved more efficiently with a lot of work (note that I personally don't even consider a timestep of 0.003 seconds to be particularly small; presumably you'd never even go above th...
- Tue Apr 02, 2013 6:57 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: Questions about collision response order
- Replies: 1
- Views: 5373
Re: Questions about collision response order
No, you are only computing the collision response (an impulse) once, based on the current states of both objects. Once you have the impulse, you apply it positively to one object and negatively to the other, and the order is irrelevant.
- Fri Mar 01, 2013 2:50 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: Soft constraint derivation
- Replies: 19
- Views: 29287
Re: Soft constraint derivation
You might do a search on this forum for the same subject on CFM and ERP; I think Dirk and I discussed it previously. IIRC, Box2D uses one derivation (including the h in the coefficients), Bullet does the opposite. Or maybe vice versa. But it can be made to work either way, so if you're deriving it i...
- Mon Oct 15, 2012 4:03 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: Stewart & Trinkle - additional resources
- Replies: 9
- Views: 23234
Re: Stewart & Trinkle - additional resources
Oops, that's who I meant! Please let me know if it hasn't shown up in your inbox.
- Thu Oct 11, 2012 7:29 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: Stewart & Trinkle - additional resources
- Replies: 9
- Views: 23234
Re: Stewart & Trinkle - additional resources
sberard- It turns out I saved a local copy of that rigid_body_lcp.pdf. Either give me a place to upload it or send me a PM with your e-mail addy, it's only about 1.1Mb.
- Fri Sep 14, 2012 2:51 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: Cloth collision detection-What is the currnt stateof the art
- Replies: 12
- Views: 22509
Re: Cloth collision detection-What is the currnt stateof the
A-ha! That's the trick I was missing. Thanks for the idea!jarno wrote:The edge versus edge case can be converted to a vertex versus plane problem by collapsing one edge to a point, and extruding the other edge in the same direction to form a quadrilateral.
- Thu Sep 13, 2012 7:02 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: Cloth collision detection-What is the currnt stateof the art
- Replies: 12
- Views: 22509
Re: Cloth collision detection-What is the currnt stateof the
Do you mind sharing how you handle the edge-edge case? My version is atrocious, but basically works.
- Mon Aug 27, 2012 9:46 pm
- Forum: Links, Papers, Libraries, Demos, Movies, Comparisons
- Topic: New research on real-time deformable body dynamics (FEM).
- Replies: 28
- Views: 70943
Re: New research on real-time deformable body dynamics (FEM)
This of course all depends on the spectral radius of the problem and the nature of the LCP, but my general experience is that it sucks for anything but perhaps large contact systems, where few other methods can be used at all. I don't know that it necessarily "sucks", but it's fairly well...
- Mon Jul 09, 2012 4:23 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: Lagrange multipliers
- Replies: 8
- Views: 16020
Re: Lagrange multipliers
Erin Catto's demonstration uses velocity-based constraints; I usually think of Lagrange multipliers as used with acceleration-based constraints, but I'm not sure of the exact definition and it could be the same thing. I think if you've modeled constraints, you've either used Lagrange multipliers wit...
- Wed Jun 27, 2012 5:15 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: using fixed-point floating point to represent position
- Replies: 2
- Views: 6713
Re: using fixed-point floating point to represent position
... or you can basically have the best of all worlds and just use doubles.
- Thu Apr 05, 2012 1:14 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: Force Computation Without Velocity
- Replies: 1
- Views: 4658
Re: Force Computation Without Velocity
If there's no velocity, those impulses are presumably going to be zero. Most game physics engines depend on solving contact impulses to resist penetration by clipping the penetration velocity to zero. I don't know what your application is, but it sort of sounds like you want to estimate the force ba...
- Tue Apr 03, 2012 4:11 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: Collisions between Characters Controllers
- Replies: 3
- Views: 5757
Re: Collisions between Characters Controllers
You might want to go back to the main forum page and read the red text regarding this sub-forum.