Real-Time Physics Simulation Forum

I did see the thread about softbodies and OGRE and kind of figured I had to go through the nodes/faces to render. The number of faces for rope is always zero (but that is probably expected since none are passed in when creating). Nodes as far as I can tell is the anchor point to each piece of the r...

Here's a code snippet to 'parse' soft bodies for rendering purposes, given your btSoftRigidWorld* as "world": /* Dummy 'graphic driver' */ struct { void DrawPoint(const btVector3&) {} void DrawLine(const btVector3&,const btVector3&) {} void DrawTriangle(const btVector3&,con...

You have to provide more information and/or code sample to reproduce the problem.

No self collisions yet sorry.

Nathanael.

Whenever I stream in new objects and insert them to the collision system I get a noticable hitch (sometimes as long as a quarter to half second). The objects come in groups of a few dozen at a time. half a second!!? that's eternity, i know peoples that use dbvt to spawn particles in their world, we...

You cannot use cluster collision on 1d soft bodies, for best results, try to model volumetric ropes with soft bodies, or better still, rigid bodies connected by constraints. Don't forget that currently, collision detection is discreet, so thinner your shape is, more likely it is to miss collisions, ...

That's shape matching, you can take a look at 'Init_BunnyMatch' and 'Init_TorusMatch' methods in SoftDemo.cpp.

Nathanael.

Compared to SAP, here's a short pro/con list: Pros: - Fast insertion, removal, update. - Unbounded world space. - Additional queries support: Ray-casting, Culling, Occlusion, LOD, etc... - One data structure for physics and everything else in a game engine. Cons: - Lot of cache misses compared to SA...

Humm, if you have time, can you post timings of btDbvtBroadphase and btSweepAxis ? and if possible a more detailed profiling output, i'd like to get to the bottom of this.
Did you called btDbvtBroadphase optimize after your static world creation?

Nathanael.

btw, FreeRealms like very nice.

Ok, here's a quick work around, if after your objects creation you call myrigidbody->setActivationState(ISLAND_SLEEPING); that should fix the issue. In the upcoming version (2.70), btDbvtBroadphase is optimized for your use case, and add the following method: bDbvttBroadphase::optimize() to be calle...

Can you provide a reproduction case ?

Thanks for the feedback,
Nathanael.

I think your basis functions should be of degree 3 ('num knots'-'num cp'-1), if the curve you expect is a "classic" Bezier like, your knots vector should be {0,0,0,0,1,1,1,1}, be careful to handle divide by zero == 0. If you look for a library, the best that i know of is http://libnurbs.so...

I guess SAP could do just fine, else you can try to google papers about "smooth particle hydrodynamic" which is a Lagrangian method to simulate fluid that require just that, very fast enumeration of interacting particles (usually fixed radius). You can try Takashi Amada SPH demo http://www...

Sorry I can't be of any more help, but some peoples had similar problem in the past, they may be able to help, try starting a new thread including 'deterministic results' in the topic .

Good luck,
Nathanael.

You need to enable soft/soft collision detection (disable by default), so for each one of your soft bodies: mybody->m_cfg.collisions |= btSoftBody::fCollision::VF_SS; Collision handling between soft bodies are not especially well handled yet, (vertex/face only), so you may have to tessellate quit a ...