Search found 66 matches

by majestik666
Tue Mar 22, 2011 9:19 pm
Forum: General Bullet Physics Support and Feedback
Topic: glue/fracture determinism
Replies: 9
Views: 4162

Re: glue/fracture determinism

after a LOT of testing/debugging/etc came out with some interesting conclusions... started by looking further at the determinism of our plugin and realized that in some circumstances (I just haven't figured out what triggers it), everything becomes very un-deterministic , even with very simple objec...
by majestik666
Sun Mar 13, 2011 2:19 am
Forum: General Bullet Physics Support and Feedback
Topic: text format serialization ?
Replies: 1
Views: 1218

text format serialization ?

Since am debugging hard my determinism problems I was wondering if it would be a good thing to be able to serialize the scene to a text format. The deserialization would be more complex obviously but in a first time being able to serialize to a text format to compare 2 scenes easily would be a reall...
by majestik666
Fri Mar 11, 2011 12:56 am
Forum: General Bullet Physics Support and Feedback
Topic: glue/fracture determinism
Replies: 9
Views: 4162

Re: glue/fracture determinism

hmmm I was really trying to avoid going that far ... I think bullet should be able to be deterministic without deleting the entire world , etc ... my sims are fully deterministic when not using the glue and I don't delete the world ... Erwin if you read this, any take on this kind of issue ? do we H...
by majestik666
Wed Mar 09, 2011 9:12 pm
Forum: General Bullet Physics Support and Feedback
Topic: glue/fracture determinism
Replies: 9
Views: 4162

Re: glue/fracture determinism

could you tell me what kind of
reset your doing ?
ie what are you resetting and when ?

would be very interested to know if i'm doing anything different ...
by majestik666
Wed Mar 09, 2011 10:08 am
Forum: General Bullet Physics Support and Feedback
Topic: glue/fracture determinism
Replies: 9
Views: 4162

Re: glue/fracture determinism

I played a bit with the fractureDemo, am not sure if the fracture itself is supposed to be deterministic but I made a simple modification to it and I get different sims every time I launch the demo ... To test, just add this code before the renderme() call in FractureDemo::clientMoveAndDisplay() and...
by majestik666
Wed Mar 09, 2011 9:51 am
Forum: General Bullet Physics Support and Feedback
Topic: glue/fracture determinism
Replies: 9
Views: 4162

glue/fracture determinism

In our current implementation of bullet I've implemented glue in a pretty similiar way as the new fractureDemo from the trunk, but I really struggle to get a stable determinism for the simulations. I have full determinism as long as I do not use glue object but when I do the determinism seems to be ...
by majestik666
Thu Jan 27, 2011 5:32 am
Forum: General Bullet Physics Support and Feedback
Topic: SoftBody Perfoprmace Hit
Replies: 3
Views: 1880

Re: SoftBody Perfoprmace Hit

Finally got around adding the garbage collect and reset of the sparseSDF, but didn't get better results. Actually now , every time I reset I get the same performance spike which makes me believe more and more that the sparseSDF grows over time and gets faster as the bodies are contained into an alre...
by majestik666
Wed Jan 12, 2011 2:39 am
Forum: General Bullet Physics Support and Feedback
Topic: SoftBody Perfoprmace Hit
Replies: 3
Views: 1880

Re: SoftBody Perfoprmace Hit

hmm didn't know about these :)

will add that and see if the issue goes away !

Thanks for the info!
Francois
by majestik666
Tue Jan 11, 2011 2:31 am
Forum: General Bullet Physics Support and Feedback
Topic: SoftBody Perfoprmace Hit
Replies: 3
Views: 1880

SoftBody Perfoprmace Hit

I was playing around with soft bodies today and noticed a quite severe performance hit on certain occasions, the situations is the following: - 20 soft body ropes connected together - some rigid bodies falling on top of them - the simulation is running inside maya The first time I play the simulatio...
by majestik666
Wed Jan 05, 2011 8:13 am
Forum: General Bullet Physics Support and Feedback
Topic: Generating a concave mesh from a point cloud
Replies: 4
Views: 3750

Re: Generating a concave mesh from a point cloud

there are many many algorithms to generate a convex hull from a point cloud,
take a look at qhull , etc ...
or this : http://www.bulletphysics.org/Bullet/php ... f=12&t=255
by majestik666
Tue Dec 21, 2010 1:57 am
Forum: General Bullet Physics Support and Feedback
Topic: link between 2 softBodies ?
Replies: 2
Views: 1948

Re: link between 2 softBodies ?

Hey Erwin, I've been playing a bit more with it and doesn't seem to cause the solver much trouble, I was running a net of ropes (10 in each direction X/Z) so 100 links (x2) between the ropes and it was running smoothly and very stable at 200fps :) so am pretty happy with it I was just wondering caus...
by majestik666
Mon Dec 20, 2010 12:53 pm
Forum: General Bullet Physics Support and Feedback
Topic: link between 2 softBodies ?
Replies: 2
Views: 1948

link between 2 softBodies ?

For our purposes, we need to be able to link one softbody to another (like linking 2 ropes together) so I implemented a link using the appendLink(node *,node *) each node * pointing to a node in a different softBody, it looks like it's working fine, am just wondering if there is a solver limitation ...
by majestik666
Fri Sep 10, 2010 9:19 am
Forum: General Bullet Physics Support and Feedback
Topic: [issue90] Glue / Fracture rigid bodies discussion
Replies: 9
Views: 6162

Re: [issue90] Glue / Fracture rigid bodies discussion

I cannot post glue code per say because it's proprietary, but the other day I was running a vehicle crashing into a building the building being 5000+ meshes and it ran at a few fps, which is more than acceptable for my environment (film). I did too make quite a few modifications to the solver for st...
by majestik666
Fri Sep 10, 2010 3:30 am
Forum: General Bullet Physics Support and Feedback
Topic: [issue90] Glue / Fracture rigid bodies discussion
Replies: 9
Views: 6162

Re: [issue90] Glue / Fracture rigid bodies discussion

We actually implemented glue here using compound shapes and using the contactAddedCallback, it does require a fair bit of tweaking but you can get pretty good results (removing contacts,etc...) I'm currently implementing a second method using breaking constraints which also requires some changes int...
by majestik666
Fri Sep 03, 2010 5:54 am
Forum: General Bullet Physics Support and Feedback
Topic: generic6DofSpringConstraint damping values
Replies: 0
Views: 1191

generic6DofSpringConstraint damping values

hi, I was playing around with this constraint today and realized I had to use very low values of damping to actually get any effect anything above 0.01 , it wouldn't have any effect and a good damping would appear with a value of 0.0025 I looked at the code and don't really understand what's happeni...