Bullet on GPU

delphi
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Joined: Sun Mar 06, 2011 12:16 pm

Re: Bullet on GPU

Post by delphi »

what is the current state of GPU support in bullet ? are there any acceleration available for physic for Blender 2.5 ? or will it be ?
kloplop321
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Joined: Sun Jan 01, 2012 7:37 pm

Re: Bullet on GPU

Post by kloplop321 »

It doesn't look like this thread has been updated since 2007, possibly 2006 regarding the status.
If this isn't live, and it isn't functioning, please remove the sticky status of this.
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Erwin Coumans
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Re: Bullet on GPU

Post by Erwin Coumans »

The GPU work on Bullet is making progress:

there is OpenCL and DirectCompute cloth:
Bullet/Demos/OpenCLClothDemo and Bullet/Demos/DX11ClothDemo

as well as a full OpenCL rigid body pipeline. The work is part of the current Bullet source code release:
Bullet/Extras/RigidBodyGpuPipeline and videos http://youtube.com/erwincoumans
Satori
Posts: 1
Joined: Sat Jul 06, 2013 9:37 pm

Re: Bullet on GPU

Post by Satori »

Hi :)


I'd like to know if Bullet 3.x (aka Bullet on GPU) is stable enough for production use. I see that it has moved from your "experiments" github directory, and I think you've been saying at GDC 2013 that it is almost ready for release.

I would like to use it with Flash through FlasCC (CrossBridge).

Bullet 3.x may not be officially released yet, but can it be used this way safely or should I wait. If so, do you have a rough idea of the official release date ?


Thanks !
Granyte
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Joined: Tue Dec 27, 2011 11:51 am

Re: Bullet on GPU

Post by Granyte »

I'm wondering if there will be a double precision compatible bullet 3 at some point
TiborDenOuden
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Joined: Wed Oct 22, 2014 7:49 pm

Re: Bullet on GPU

Post by TiborDenOuden »

I am trying to write a physics engine in WebGL here : http://www.borbitsoft.com/
Do all the heavy lifting on the gpu using shaders.
The best way to run the demos is to use Chrome or Opera on a pc with a recent graphics card and up to date drivers.
(Although IE 11 displays true, its WebGL implementation is not mature enough to run the tech demo's, have to fix that)

One of the hardest things I found was debugging the shaders.
I ended up by writing lots of tests and I build a system where a shader was run multiple times
to emit certain key variables selected by a debug id.
One of the issues with that was that due to the extra complexity of the added ifs the shader would
not compiler or emit bogus data.
Also the count of bugs encountered compared to working in C/C++ surprised me.
Now with the DX11 backend for WebGL in Chrome and the extra massaging the angle team (https://code.google.com/p/angleproject/) applies to the shaders this has improved a lot.

How do you debug the gpu code in bullet ?
elect
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Joined: Tue Aug 25, 2015 6:50 am

Re: Bullet on GPU

Post by elect »

Quick question, if opencl support is so fragile, why don't we use opengl compute?
Basroil
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Joined: Fri Nov 30, 2012 4:50 am

Re: Bullet on GPU

Post by Basroil »

elect wrote:Quick question, if opencl support is so fragile, why don't we use opengl compute?
For one, opengl compute support is even more fragile, having only been added in 4.3 and not really designed for this type of application. So far the only real competitor is CUDA, but that of course requires Nvidia hardware, and the DirectCompute/OpenGL Compute systems are not quite ready to tackle non-trivial physics (but they excel at particles and even particle based fluids and solids)
elect
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Joined: Tue Aug 25, 2015 6:50 am

Re: Bullet on GPU

Post by elect »

Basroil wrote: For one, opengl compute support is even more fragile, having only been added in 4.3 and not really designed for this type of application. So far the only real competitor is CUDA, but that of course requires Nvidia hardware, and the DirectCompute/OpenGL Compute systems are not quite ready to tackle non-trivial physics (but they excel at particles and even particle based fluids and solids)
I find compute shaders much more interesting than opencl. It extends an already stable API, supports natively GLSL types, can be run between different graphic stages and has access to all the opengl input infrastructure.

It is really a huge advantage for me, given one uses bullet in combination with graphic 95% of time.
abhirajbishnoi
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Joined: Fri Mar 13, 2020 6:02 pm

GJK-EPA on GPU Robust in latest Bullet version?

Post by abhirajbishnoi »

Hi,

I'd like to use the GJK-EPA algorithm to computing the penetration depth between pairs of colliding bodies (convex polytopes), specifically for robotics applications as my master thesis. To accelerate the collision detection process, the plan was to do implement this using GPUs and CUDA. I see that Bullet already has an OpenCL version of the GJK-EPA algorithm and I was thinking or reusing this as is or as a reference to implement a CUDA variant. Does anybody who has used this particular algorithm on Bullet for computing penetration depths on GPUs know if it runs into numerical stability issues? Is it safe to use as is? Thanks a lot for your inputs and time in advance!

Warm regards,
Abhiraj
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