Multi-threaded operations in Blender

(Disclaimer: I’m not a lawyer) The way I read the GPL all they have to do is give you the option to easily get the corresponding source code through normal software distribution channels, they don’t have to distribute it with the package. SVN lets you check out a particular revision of the code at any time, so I think this fulfills the criteria.

But it is good that the BF gives you the actual version (which Zalamander linked to above) their binary was built from and downloadable from their website as well just so there is no confusion.

Excuse me for mini-hijack, but where is “system-info.txt” written to? A thorough search on OSX comes up with nothing. Am I missing something?

In fact there’s no system-info.txt file created, it’s working the same way of those textures you create in the UV/Image Editor -> Image -> New Image, as long as you don’t save the newly created image manually, there’s no actual file.

To see the content of that “floating” system-info.txt, change the 3D View into the Text Editor and click on that button then select the " file "

You can then save it as an actual file from there.

@Sanctuary: Ahh… I figured it would be something like that. I hardly ever use the text editor. I did look there at first, but since it was blank, I moved on. Didn’t think to see if it was a file in memory.


i build Blender from trunk using scons; how exactly do i enable openMP before building?

n00b here, sorry

but… is not everything multithreading ?

Viewport is not multi threaded ?


Hi ohsnapitsjoel, try



I don´t build with scons for a long time but found old included this tag.

Cheers, mib.

Baking cloth simulations needs to be multi-threaded. I am running one now it does not appear to be a multi-threaded operation.

Cloth simulation is multithreaded

where in the blender 2.68 directory would I find I did a quick search and can’t seem to find it

You could only switch OpenMP on or off if you compile Blender by yourself, do you?
Than you have to create the

Cheers, mib.

is it off by default?

I have a 8 core cpu…

No, it is on per default.
OpenMP help on multi core systems but is not really multi threaded like rendering or fluid simulation.

Cheers, mib.

you need gcc 4.6 or later then replace your CC = ‘gcc-4.2’ and CXX = ‘g+±4.2’ accordingly to you gcc install.

I was thinking that one way multithreading could speed up things is by LOD management, if LOD is done on its own thread, then the viewport gets the speed up LOD offers and the speed up from pushing the work onto another thread,

When I do a cloth sim, it is only using one of my 8 cores. But when I render it uses all my threads.

Same, and that is the way it has always been. If these things were multi-threaded, it would be a massive speed boost. Perhaps when the physics get upgraded (Planned for sometime in the 2.7 series).

OpenMP is a rather outdated framework for threading operations if I recall correctly. There are better options out there, but none that compares to writing well-threaded code manually.

LOD in the viewport, makes huge scenes possible , and will help modernise the BGE…

I can’t wait for harmony and candy to merge…