Search found 23 matches
- Tue Oct 21, 2008 6:32 am
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: what does "sweep" and "prune" mean ?
- Replies: 5
- Views: 8708
Re: what does "sweep" and "prune" mean ?
I think it was Christer Ericson who said the algorithm should really be called "sort and sweep" instead of "sweep and prune". To me it looks more like "sort and prune" :) I have said that, and the reason I've said that is because Baraff was the first one to describe th...
- Tue Oct 21, 2008 6:21 am
- Forum: Links, Papers, Libraries, Demos, Movies, Comparisons
- Topic: Universal SIMD Mathlibrary
- Replies: 6
- Views: 11187
Re: Universal SIMD Mathlibrary
Mathfunctions for single precision floating point vector datatypes are provided for the SIMD-platforms x86 (SSE2), PowerPC and Cell. In most cases, speed and/or accuracy compare favourable with existing SIMD-libraries (MacOS Accelerate Framework, Cell SDK). Most of the algorithms are based on those...
- Sun Sep 09, 2007 8:36 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: generic swept sphere collision detection algorithm.
- Replies: 4
- Views: 8394
Re: generic swept sphere collision detection algorithm.
All that sphere collision talk got me thinking a little. I am thinking of an algorithm to collide spheres against over convex shapes, which is similar to the GJK algorythm, and is an iterative method. However it requires square roots to find the point of contact (due to the sphere's nature). It's u...
- Thu Aug 02, 2007 5:44 am
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: Multi SAP
- Replies: 22
- Views: 45172
- Sat Jun 16, 2007 6:12 am
- Forum: Links, Papers, Libraries, Demos, Movies, Comparisons
- Topic: Rotational penetration depth
- Replies: 5
- Views: 10996
Re: Rotational penetration depth
Interesting concept, calculating rotational penetration depth, rather then just translational[...] Here's another on the same topic: http://www.geometrie.tuwien.ac.at/nawratil/gpdcbokg.pdf This one is outstanding in the sense that it manages to make the presentation just about unreadable by overloa...
- Sat Mar 10, 2007 11:16 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: accuracy of collision detection: Bullet vs. Solid
- Replies: 17
- Views: 26646
- Sat Nov 04, 2006 7:21 am
- Forum: General Bullet Physics Support and Feedback
- Topic: Stackless trees
- Replies: 10
- Views: 14682
- Sun Oct 29, 2006 11:45 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: Interval arithmetic.
- Replies: 1
- Views: 6546
Re: Interval arithmetic.
Does anyone know of any papers/text regarding interval arithmetic? My maths skills are fair, so the easier to read the better. Oh, there are lots of papers! For starters, try the papers by Tim Hickey . E.g. this one: Hickey, Timothy. Qun Ju. Maarten van Emden. ?Interval Arithmetic: From Principles ...
- Sun Jun 25, 2006 7:35 pm
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: Fast Realtime bounding volume approaches ?
- Replies: 4
- Views: 7711
Re: Fast Realtime bounding volume approaches ?
I can build an optimal sphere quickly, but most clothing doesn't really conform to this kind of test well. most cloth is planar majority of the time. AABB too is not optimal in world space.. I think I need to use an arbitary BB. That is Convex hull of 6 planes. Hi Andi! I probably wouldn't try to c...
- Sun May 28, 2006 6:33 pm
- Forum: General Bullet Physics Support and Feedback
- Topic: collision with very big static object
- Replies: 13
- Views: 24834
You are probably right and I am wrong. :( Almost humble?! Doesn't sound at all like the child who first posted this belligerent post: Wow, thanks you for letting it me know about that algebraic identity (I feel so much empowered now). Is this a principle you came up with? Would that be the Ericson?...
- Wed May 24, 2006 9:22 pm
- Forum: General Bullet Physics Support and Feedback
- Topic: collision with very big static object
- Replies: 13
- Views: 24834
- Wed May 24, 2006 7:15 am
- Forum: General Bullet Physics Support and Feedback
- Topic: collision with very big static object
- Replies: 13
- Views: 24834
As I remember it was said that by using Voronoi space search the numerical errors due to lost of precision in the analytical distance calculation are avoided. In fact it can be proven that both methods are mathematically equivalent. You misunderstood. It is trivially the case that we can have two e...
- Sat Apr 29, 2006 6:01 am
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: Ageia PPU convex-convex performance
- Replies: 1
- Views: 6353
Re: Ageia PPU convex-convex performance
- Peak instruction bandwidth: 20 Billion/sec - Sphere-sphere collisions: 530 Million/sec max - Convex-convex (complex collisions): 533,000/sec max [...] The convex-convex collision information is interesting. I guess it refers to a convex-convex case of up to 32 vertices. It doesn't tell if that is...
- Fri Feb 03, 2006 7:55 am
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: Gino's Book - Robustness section
- Replies: 4
- Views: 9150
Re: Gino's Book - Robustness section
So, from page 59 I'm not understanding what Gino is trying to explain in the phrase that starts with "Assume". I'm not Gino, but perhaps I can explain anyway. Let's start by nothing that a typical floating point operation 'op' introduces an error along the lines of: fl(a op b) = (a op b)(...
- Fri Jan 20, 2006 6:46 am
- Forum: Research and development discussion about Collision Detection and Physics Simulation
- Topic: Interval arithmetic, interpenetration, repositioning
- Replies: 8
- Views: 14489
Re: Interval arithmetic, interpenetration, repositioning
2. Why is it preferable to check whether the point of impact is inside the edge/triangle only after the time of impact (with the infinite line/plane) has been determined? The way I see it, this allows some collisions to be missed. For example, a vertex that's supposed to collide with a triangle mig...