Search found 58 matches

by Eternl Knight
Tue Oct 23, 2007 3:45 am
Forum: General Bullet Physics Support and Feedback
Topic: Question: Simulating water
Replies: 26
Views: 22612

Re: Question: Simulating water

Looks pretty damn good. Is this code Bullet or other engine specific?

--EK
by Eternl Knight
Wed Oct 17, 2007 3:08 am
Forum: Research and development discussion about Collision Detection and Physics Simulation
Topic: Force Limited Velocity Constraints: what are they??
Replies: 7
Views: 5248

Re: Force Limited Velocity Constraints: what are they??

Intuitively, that kinda makes sense. When you think of moving your leg, you think of the speed you WANT it to move. Which is why you will stumble/trip/whatever when something impedes the "expected velocity" of your foot.

Sounds interesting :)

--EK
by Eternl Knight
Wed Oct 17, 2007 1:17 am
Forum: General Bullet Physics Support and Feedback
Topic: Height-Field Bug/Feature
Replies: 7
Views: 4261

Re: Height-Field Bug/Feature

Yes, I have implemented the "column-based" approach (where there is a triangular column for every surface triangle). It has a couple of problems which need to be resolved. Firstly there is still an issue that when an object is completely "submerged" under the terrain, the contact normal should point...
by Eternl Knight
Sat Oct 13, 2007 12:46 am
Forum: General Bullet Physics Support and Feedback
Topic: Can you help testing Bullet 2.63-RC1?
Replies: 6
Views: 3930

Re: Can you help testing Bullet 2.63-RC1?

Whether this is a MSVC 7.1 issue or something else I am not sure of; but the "libquickstep" will not compile in MSVC 2003 (i.e. MSVC 7.1) as <intrin.h> does not exist. You also need to add #include <memory.h> in order for memset to be defined in the "#ifdef _MSC_VER" (the __GNUC__ version has #inclu...
by Eternl Knight
Sat Oct 13, 2007 12:20 am
Forum: General Bullet Physics Support and Feedback
Topic: "Dynamic Compound Convex" Questions
Replies: 4
Views: 2669

Re: "Dynamic Compound Convex" Questions

If you make those columns tall, you might get objects wedged between them with only horizontal contact normals. The object will then ping-pong back-and-forth falling into the abyss. I have thought of this and is something I have discussed with Erwin (briefly) in the beginning. For any face but the ...
by Eternl Knight
Thu Oct 11, 2007 2:09 am
Forum: General Bullet Physics Support and Feedback
Topic: "Dynamic Compound Convex" Questions
Replies: 4
Views: 2669

"Dynamic Compound Convex" Questions

I am working on implementing a volumetric approach to the height-field collision shape so that fast moving objects are detected as colliding with the terrain even if they pass through thin shell of triangles making up it's surface. I am making a new shape class for this as the existing height-field ...
by Eternl Knight
Wed Oct 03, 2007 1:34 am
Forum: General Bullet Physics Support and Feedback
Topic: Question: Simulating water
Replies: 26
Views: 22612

Re: Question: Simulating water

Yeah, I am looking at it already. Hence the discussion about trying to integrate the idea of buoyancy & volumetric terrains.

Will try to get a prisms version working in the next couple of days (sorry, but my baby boy is sick so time is limited to the 2.5hrs train trip I do to/from work)

--EK
by Eternl Knight
Tue Oct 02, 2007 11:30 pm
Forum: General Bullet Physics Support and Feedback
Topic: Question: Simulating water
Replies: 26
Views: 22612

Re: Question: Simulating water

I've been looking at changing the height-field collision detection & resolution (as detailed in another thread) and this seems to have similar requirements and/or implementation details. Perhaps there is a way to have both bouyancy and "volumetric" height-fields catered for in the same fashion? The ...
by Eternl Knight
Fri Sep 28, 2007 4:53 am
Forum: Non-technical forum and license/patent discussion
Topic: Position Based Dynamics: Patent
Replies: 56
Views: 59884

Re: Position Based Dynamics: Patent

At any rate, let's keep the discussion about "a patent seeker" rather than about me specifically. While this is an admirable goal - it will be hard, especially considering you seem to be the only one arguing FOR the application of patents in this particular field of interest on the forums. As such,...
by Eternl Knight
Thu Sep 27, 2007 7:08 am
Forum: Non-technical forum and license/patent discussion
Topic: Position Based Dynamics: Patent
Replies: 56
Views: 59884

Re: Position Based Dynamics: Patent

Now that we are in a thread more suited to the topic at hand - I'll let fly... er, "discuss civilly" :P my thoughts on patents. Please note that I am not attacking you in any of this (I don't know you, so for me it is silly to get personal about things), but I will be blunt about how I feel about th...
by Eternl Knight
Thu Sep 27, 2007 6:25 am
Forum: Non-technical forum and license/patent discussion
Topic: FastLSM soft body physics (source code available)
Replies: 14
Views: 18715

Re: FastLSM soft body physics (source code available)

Unfortunately Alec, once out of the bag - I think it quite problematic to get the proverbial cat it back in there. If Erwin were to remove the thread, it could be construed as "hiding evidence" that people knew about said patent. Given that some of the more knowledgeable contributors to these forums...
by Eternl Knight
Thu Sep 27, 2007 4:16 am
Forum: Non-technical forum and license/patent discussion
Topic: FastLSM soft body physics (source code available)
Replies: 14
Views: 18715

Re: FastLSM soft body physics (source code available)

I don;t know if this is required by Erwin or Alec, but I think we should keep the topic about either the paper/algorithm/code or why we cannot look at the paper/algorithm/code. While I would love to discuss the merits of software patents on primarily mathematical conveniences (or merit lack thereof)...
by Eternl Knight
Wed Sep 26, 2007 11:15 am
Forum: Non-technical forum and license/patent discussion
Topic: FastLSM soft body physics (source code available)
Replies: 14
Views: 18715

Re: FastLSM soft body physics (source code available)

There is a big difference to discussing papers and algorithms that "may" be patented to those that are clarified as explicitly being patented. And that is what will prevent anyone here being able to discuss your paper/algorithm with you. You mention that not only have you covered your algorithm with...
by Eternl Knight
Wed Sep 26, 2007 12:45 am
Forum: General Bullet Physics Support and Feedback
Topic: Height-Field Bug/Feature
Replies: 7
Views: 4261

Re: Height-Field Bug/Feature

There is still some "special case" stuff that would only apply to height-field processing (namely the collision normal needing to point UP for all contacts but those on the single surface triangle). As long as the callback allows for sucvh an override - I think this will be a nice clean solution to ...
by Eternl Knight
Tue Sep 25, 2007 11:48 pm
Forum: General Bullet Physics Support and Feedback
Topic: Height-Field Bug/Feature
Replies: 7
Views: 4261

Re: Height-Field Bug/Feature

The solution I was thinking of (which you mentioned) was to collide with triangular prisms rather than just the surface triangles. The issue I am trying to resolve with this is that the contact normal for all faces (except the surface triangle) would need to be "up" in order to push penetration back...