Physics in blender

Why is it sooooo slow? Is there planned GPU physics support? Even a lower range old geforce 8600 can process physics faster than a brand new quad core cpu can in blender… its kinda sad actually. For example fluid physics… come on seriously? to get anything even remotely water like it takes hours and hours to bake ten seconds worth, however i know for a fact i can run a gpu fluid sim at high frame rates.

Maybe you should either break out the checkbook or your coding skills to fix this ‘problem’.

And, you know, there’s always ‘You get what you pay for’…

There where OpenCL comes in. Expect in the distant future a steady move towards OpenCL.

@ Sycosys: Blender is not for hobbyists but for professionals with the releated equipment. Did you also try another software like Houdini? Or Maya Fluids? They have equal timings for simulation.
Regarding fluid: You can always use low res (25 or something) for display and let the high res simulaiton take place over night. There is a reason why big studios own their own renderfarm/cpu cluster!

It’s slow because every tool has limitations. To improve the speed, you or someone else would have to optimize the code voluntarily, or one party might pay another to do the work.

Either way, it takes time … just be glad you have access to a slow simulator rather than none at all, in an open source package (esp. considering that there are commercial apps that don’t even have Fluid simulation, or have a limited implementation, or only have it through an expensive plug-in …).

I’m new to Blender and you brought something to my concern, I haven’t tried physics yet, is it always slow like how you explained it ? does it apply to everyone else too ?

Looks like the result of another badly worded post. :no:

Sometimes I wish I were a coder:cool:

no it doesn’t

@ Cire: no comment :wink:

Daniel / Genscher

(also Blender Fluid maintianer & Smoke introducer)

You should really read up about physical simulations and the algorithms behind each simulation.

If your trying to compare technical demo’s from companies such as Nvidia, then your in for a very big shock.

Personally my Q6600 chews through the calculations, even when on very high setting’s, Perhaps a video card could run it faster, if it were heavily optimized for that kind of hardware. But as it is, at the moment, if your finding it hard to sit and wait for simulations to run through you either need to, like i said, read into what is happening and try to develop a faster algorithm (marching cuboid, or something along those lines) or buy better hardware.

Btw read up on some of the articles from studios, for example the 10,000 balloons in up took a hell of a long time to compute and that was probably across a farm of hundreds of computers, each with multiple cores.

GPU acceleration appears to be on the horizon for commercial applications, and I think there’s a couple of blender devs looking into OpenCL for Blender. Also, have you seen the new smoke simulation stuff?

The new Bullet 2.75 does have OpenCL support. And fluid simulation is coming to Bullet with same interactions that soft bodies have (i.e. two way interactions).

So real time fluid simulation could be integrated into the future.

It also possible to get Blender to detect whether a GPU supports OpenGL 3.x and higher. If it doesn’t then fall back to old GPU support. This will bring OpenGL 3.x with OpenCL feature into Blender (so for example OpenGL 3.2 with OpenCL brings Direct3D 11 kind of features into the BGE). But no one that I know of is working on this feature. And it should really be done later on when 2.5 is released and more stable versions come out.


I’m confused … did you think my post was directed at you? It was a response to the original poster.

And since I can’t say it enough, thanks again for all of your awesome work!

Really? Maybe 99% of it’s users should stop using it then since it’s not something they should be using.


I imagine he meant ‘Blender is not only for hobbyists but also for professionals with the related equipment!’

Let’s hope so. I would still like to be considered a legitimate user.


I’m sure that isn’t what Daniel meant. From what I understand of Blender / NaN history, it has always been professional software. At no time did it stop being a professional 3D software suite and start being hobbyist software. Just because it is free now doesn’t mean it is any less professional.

Heck, if Blender were only for hobbyists, the GUI learning curve would have been flattened long ago.

Edit: Dang…Too slow.

I know blenders history. What is and is not “professional” software? A question I really find quite preposterous.


I suppose “professional” software is designed to support a business or profession. If Blender was designed to support a hobby, I would then consider it “hobbyist” software. But let’s not argue about semantics.

p.s. Why can’t I participate in discussion without being involved in silly arguments?

I think mainly it’s just your name …but that picture doesn’t help, either. :slight_smile: