Search found 10 matches
- Mon May 08, 2017 3:37 am
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: Johnson's distance algorithm: can't find smallest simplex
- Replies: 4
- Views: 40258
Re: Johnson's distance algorithm: can't find smallest simple
Hi Gino, I'm already checking for duplicate support points as suggested in your book, to prevent GJK from looping indefinitely*. I'm not checking for the closest point being significantly closer to the origin than the last closest point, but Erwin suggested that too in a different thread so it's som...
- Tue May 02, 2017 2:23 am
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: Johnson's distance algorithm: can't find smallest simplex
- Replies: 4
- Views: 40258
Re: Johnson's distance algorithm: can't find smallest simple
I have added some comments to make the code a bit easier to understand. I should probably do a little refactoring.
- Mon May 01, 2017 11:30 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: Johnson's distance algorithm: can't find smallest simplex
- Replies: 4
- Views: 40258
Johnson's distance algorithm: can't find smallest simplex
I'm having a problem with Johnson's distance algorithm where it sometimes fails to find the smallest simplex containing the point that is closest to the origin. In 2D, this means I get a simplex of size 3 that does not surround the origin and can't be reduced any further by the algorithm (as impleme...
- Thu Apr 20, 2017 1:31 am
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: GJK: reappearing support points and termination condition
- Replies: 2
- Views: 7798
Re: GJK: reappearing support points and termination conditio
I'm not checking for progress toward the origin right now, but I'm doing everything suggested by Gino in his "numerical GJK" example. Also, I'm doing this in 2D so I exit as soon as the reduced simplex becomes a triangle. Here's what my GJK function looks like right now, including all term...
- Wed Apr 19, 2017 5:23 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: GJK: reappearing support points and termination condition
- Replies: 2
- Views: 7798
GJK: reappearing support points and termination condition
I'm having a problem in my GJK implementation where support points reappear periodically in an endless loop, a situation described in pages 143 - 145 of Gino's book, Collision Detection in Interactive 3D Environments . I have added the check for duplicate vertices described in page 145 of the book, ...
- Fri Jul 31, 2015 6:19 am
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: Johnson's Distance Algorithm: What am I doing wrong?
- Replies: 1
- Views: 5870
Re: Johnson's Distance Algorithm: What am I doing wrong?
I'm also asking on Stack Overflow.
- Fri Jul 24, 2015 6:10 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: Johnson's Distance Algorithm: What am I doing wrong?
- Replies: 1
- Views: 5870
Johnson's Distance Algorithm: What am I doing wrong?
Given a simplex {y1, y2} where: y1 = (1,-1) y2 = (1,1) The closest point of its affine hull to the origin should be (1, 0), but that's not what I get: Δ1 = 1 Δ2 = Δ1 * ((y1 - y2) . y1) = 2 Δx = Δ1 + Δ2 = 3 λ1 = Δ1/Δx = 1/3 λ2 = Δ2/Δx = 2/3 v = λ1*y1 + λ2*y2 = (1, 1/3) I must be doing something wrong...
- Wed Dec 03, 2014 4:42 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: Continuous GJK for spherically extended objects
- Replies: 1
- Views: 6486
Continuous GJK for spherically extended objects
Is there a way to perform a ray cast as described in Gino Van Den Bergen's Ray Casting against General Convex Objects , against spherically extended objects without having to calculate support points for the enlarged objects? With GJK you can adjust the termination condition to account for the sligh...
- Sun Apr 18, 2010 9:21 pm
- Forum: General Bullet Physics Support and Feedback
- Topic: ClosestNotUsRayResultCallback (code)
- Replies: 2
- Views: 3880
Re: ClosestNotUsRayResultCallback (code)
BTW - Is there an official place to submit contributed code?
- Fri Apr 16, 2010 2:46 am
- Forum: General Bullet Physics Support and Feedback
- Topic: ClosestNotUsRayResultCallback (code)
- Replies: 2
- Views: 3880
ClosestNotUsRayResultCallback (code)
I wish to contribute the following code to Bullet's official sources. This code is based on Bullet's own btKinematicClosestNotMeRayResultCallback, but any part of it that may be considered original I hereby place into the public domain. ClosestNotUsRayResultCallback.h: #ifndef CLOSESTNOTUSRAYRESULTC...