Unix renderfarm, all free software - how?

JustHalf

I was wondering if it would be possible to create an entirely free-software driven renderfarm of x86 machines clustered together? The renderer would have to be capable of film-quality rendering.

I was also wondering as to the ideal modelling / character animation packages for these?

Zaltais

Hi JustHalf,

I've no idea how you'd go about it, but this is definately possible. Weta Workshop used what is now (apparently) the largest server farm in the southern hemisphere for rendering scenes from the Lord of the Rings films....

Check out this:

Linux’s latest coup involves its central role in the production of The Lord of the Rings, for which Weta Digital, a New Zealand company, created the special effects. Weta’s 160 digital artists generated roughly one terabyte of data per day with dual-processor SGI 1200 servers running Linux.

Weta used PRMan, the Linux version of Photorealistic Renderman, to render the images for the trilogy’s first installment. According to chief technology officer Jon Labrie, Weta reduced the cost of rendering to a tenth of that for SGI’s Octane workstations. Weta bases its primary rendering resource on SGI 1100 and 1200 Linux-OS-based servers. Having started with 32 dedicated processors, the FX house currently runs 192 dual-processor Pentium SGI servers that render frames 24 hours a day, seven days a week.

From here

There's probably a lot more stuff out there, but it's certainly possible.....

fixer

you want to build a renderfarm but you don't have a software package chosen yet? kinda the cart before the horse, don't you think?

Most of the post & fx studios I've been at have used racks of servers as well as unused artists workstations for rendering, but not using clustering. they have used queuing systems that dish out frames to available cpus and track results.

artists submit jobs to the queue, someone assigns a priority and number of cpu's available to that job (cpus are limited resources and must be prioritized). when a cpu is free, it sends in a request for a new frame, collects the various elements and script files, performs the required operation, saves out the frame, then repeats the cycle.

Zaltais

As it happens I was reading an article on 'Grid computing' yesterday, which may also be an avenue worth considering - similar to fixer's suggestion but can link in with desktop pc's spare cycles as well rather than being explicitly 'queued'.

Similar to the method used by the SETI @ Home program.....

In this months 'Linux Pro' - which is a supplement in 'Linux Format'

I can scan & email it to you if you're vaguely interested.....


<edit>
Sorry just re-read fixer's post and that's kinda what he said....
[Note to self - read things before launching off into another tangent.]
</edit>

JustHalf

Originally posted by fixer
you want to build a renderfarm but you don't have a software package chosen yet? kinda the cart before the horse, don't you think?

Not really. I'd like to have a renderfarm for rendering, as opposed to a single PC, therefore changing the requirements for what renderer I will require.

Am I making sense?

I'd also like recommendations as to good character modelling and 3D animation tools that are free software.

Originally posted by fixer
Most of the post & fx studios I've been at have used racks of servers as well as unused artists workstations for rendering, but not using clustering. they have used queuing systems that dish out frames to available cpus and track results.

We'd need a cluster for other work too, so I'd like to have the rendering as another job on the cluster.

sirlinux

well as long as your rendering software forks you should look at www.mosix.org and www.openmosix.org it behaves relatively similar to an SMP, and as well as that you dont have to rewrite anything.

drjolt

Look, there's three main pieces involved in these setups:

1) Creation
2) Job distribution
3) Rendering

Openmosix, beowulf, etc. etc. etc. etc. can only do job #2. You still need parts #1 and #3. The movie studios may well be giving their artists linux pcs to doing job #1 on, but they are using expensive commercial proprietary software on those machines. Similarly, they may be using linux pcs to do job #3, but they are using expensive commercial proprietary software on those machines. They might just be using free software on linux pcs to do job #2, but that's it.

TheWarden

Well I'm working for a company that have quite a large renderfarm so I can probably give you some pointers.

Free rendering software could be tricky - povray is the most famous but it's hardly film quality. Lightwave 3D include a free network renderer which doenst require a license (they have just released a Linux version). I believe Maya has a free mental ray network renderer too... but I'm not sure.

As for submitting jobs. Look up Sun's "Grid Engine Enterprise Edition". It's free and works very well for DCC. We use pixar's Alfred which costs lots of money - to be honest SGE is better.

If the farm starts to increase in size (>10 machines) then look at diskless booting. We are running 250 machines from a single root filesystem from a central server. We only use the macine's local harddrives for swap and /tmp.

Hope this is of help.

Oh by the way diskless booting rules. I write this from my diskless Linux machine

Zombrex

You should check out Blue Moon Rendering Tools a freeware RenderMan compatible renderer for linux and windows. It has a program for rendering over a render farm.

www.bmrt.org - Website seems down at the moment but you can get it from here)

It is freeware but NOT opensource so read the licence agreement.

It has no software tools it is purely a renderer, so u will have to build your scenes using another package.

For a complete package the best opensource (ie free) option would be Blender - www.blender3d.org - though I don't know if the renderer has options for rendering over a farm. Still u can always use the modeller and export to a RenderMan compatible renderer such as BMRT.

JustHalf

BMRT looks great, thanks for the information.

ObeyGiant

Originally posted by Wicknight
For a complete package the best opensource (ie free) option would be Blender - www.blender3d.org - though I don't know if the renderer has options for rendering over a farm. Still u can always use the modeller and export to a RenderMan compatible renderer such as BMRT.

NaN (the original developers of Blender) did give out a rendering daemon. Unfortunately, since becoming open-source, a lot of the stuff that wasn't directly related to the basic blender project has been a little up in the air.

On the projects page, they say that they're working on the network rendering system. They haven't released anything yet, but they say the code for the original NaN daemon is in CVS. Check it out: here

JustHalf

Does anyone know where I can get information on using the RenderMan interface directly, and what this specific interface is capable of?

RicardoSmith

Is there an interface? I thought you had to script everything?

JustHalf

The scripting language being one of at least two interfaces. What I'm talking about is bypassing the modeller - animator program.

I was wondering how best to access it, and what it was capable of. Of course, I am very tired, and I now realise that the best idea is just to RTFM (the Renderman Specification from Pixar).

RicardoSmith

Originally posted by JustHalf
The scripting language being one of at least two interfaces. What I'm talking about is bypassing the modeller - animator program.

I was wondering how best to access it, and what it was capable of. Of course, I am very tired, and I now realise that the best idea is just to RTFM (the Renderman Specification from Pixar).

Sorry I took you literally. Any of the applications I ever used that output to renderman simply ouput text based renderman script/scene files. There was no interaction between them. You had to script the shaders and materials in most cases yourself. That was a few years back and I'm not familar with how more modern apps like Maya do it these days. They seem to have some custom interface for it on the renderman site.

Any one I know doing 3D/animation stuff these days doesn't use it at all. As far as I remember anyone I used to know that did basically wrote their own software for working with render man. I used to have a very early version of renderman years ago, but its long since been lost. Twas in the days before it was well known, and wasn't really all that good. I thing it came with some early Autodesk software I was using at the time for rendering/animation.

All the current interfaces are available as downloads from the pixar/rendrman site. https://renderman.pixar.com/

Incidentally its not cheap at 5000 dollars.

oslin

i saw a opensource implementation of rendermans api on source forge a while back don't know how active this is.
Might be worth a shot.
nils

fixer

not free, but ShadeTree is a gui shader writing tool from my buddy Erco. http://www.cinegrfx.com/