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mikkelen
08-01-2015, 06:56 AM
Any news on multi-threading and Bullet?

mikkelen
08-11-2015, 03:16 AM
...anyone with any knowledge on the subject?

MSherak
08-11-2015, 01:05 PM
...anyone with any knowledge on the subject?

Currently BULLET has dropped multithreaded support for 2.8x and 3.0.. Looks like 2.8x is staying single threaded to keep the API working on all platforms. 3.0 is moving to OpenCL only which means any GPU card can work with it and is replacing multithreading cpu functions.


QUOTES
"Requirements for Bullet 2
A C++ compiler for C++ 2003. The library is tested on Windows, Linux, Mac OSX, iOS, Android, but should likely work on any platform with C++ compiler. Some optional demos require OpenGL 2 or OpenGL 3, there are some non-graphical demos and unit tests too."

"Requirements for Bullet 3
The entire collision detection and rigid body dynamics is executed on the GPU.
A high-end desktop GPU, such as an AMD Radeon 7970 or NVIDIA GTX 680 or better. We succesfully tested the software under Windows, Linux and Mac OSX. The software currently doesn't work on OpenCL CPU devices. It might run on a laptop GPU but performance is likely not very good. Note that often an OpenCL drivers fails to compile a kernel. Some unit tests exist to track down the issue, but more work is required to cover all OpenCL kernels."


I would expect 3.0 not showing up in commercial versions of software until it is out of beta phase. There was/is and experimental 2.83 with multithreading but it crashed a lot, again don't expect to be placed in a commercial product unless it was placed as experimental. Even then I would not want a simulation to crash my software.

hdace
08-17-2015, 11:24 AM
Oh. Golly. My eyes glaze over whenever anyone mentions C++. But I think you just said that a future version of LW might have Bullet using my nVidia cuda thingy to process dynamics. Doesn't that mean... that something taking a minute or two now might take, like 15 seconds or something? You sure got me excited!

MSherak
08-17-2015, 11:49 AM
Any package that has Bullet can place version 3.0 in when released and be able to use ANY GPU for calculations using OpenCL. (No CUDA thank god) SO yes in theory if NTDev places Bullet 3.0 in when release you will get faster results so long as you have a OpenCL compatible driver for your video card. Don't hold your breath since Bullet 3.0 release date has not been announced.

Also when released expect time after that for developers to update it in their software.

Greenlaw
08-17-2015, 01:39 PM
Thanks for the news!

I know what you described is pretty far down the road but it sounds like good times ahead. :)

G.