A global illumination (GI) renderer comparison

[wahn]

Hi,

my name is Jan Walter. I currently work (again) for The Mill in London. I did work in film (MPC, Mill Film, Digital Domain) and commercials (The Mill). I do know a lot about rendering (5 years @ mental images, but I also know the RenderMan world, work on MtoA [Maya to Arnold], and tested many other renderers [for fun]). It started as a hobby and later became more serious. I once worked with NaN (probably 12 years ago) at a time when Blender wasn't open source, but free to use. I still use Blender in my spare time to do render comparisons, but I obviously have access to all the commercial packages (Houdini [my favourite], Maya, XSI, even 3DS Max).

Anyway, I give workshops at the Filmakademie in Ludwigsburg and tech talks at FMX, and recently I showed a lot of different renderers (including Luxrender) in action. I have a lot of stuff in repositories on Bitbucket and I'm happy to share scenes, experience etc. with you. Unfortunately I can't grant public access to most of the stuff right now because Arnold isn't out for the public and some content is Arnold related (API and ASS files). But if you contact me directly and ask for Luxrender (or other renderer related files - except the Arnold ones) I'm happy to give you access to whatever you'd like to experiment with. Email is jan at janwalter dot com ...

Here from the README file of https://bitbucket.org/wahn/radiance_vs_ ... /wiki/Home:

A global illumination (GI) renderer comparison
----------------------------------------------

The materials collected here was used for a workshop given at the
Filmakademie Ludwigsburg in Germany (on Januray 31st, 2012):

http://www.filmakademie.de/
Filmakademie Baden-Württemberg
Akademiehof 10
71638 Ludwigsburg

In the meantime I updated and added more files to automate the rendering of
test files for a tech talk I gave at FMX 2012 (http://www.fmx.de).

Here is a link to a summary of the tech talk (which was given on May 10th):
http://www.fmx.de/program/event-details ... Event.html

The slides for the presentation are available for download from
http://www.janwalter.com/Download/index.html and as soon as Arnold
will be publicly available I will grant public access to this
repository and my Blender importers/exporters (currently RAD import,
RIB and ASS export) which are on Bitbucket as well:
https://bitbucket.org/wahn/blender-add-ons.

The tech talk covered following renderers:

- Radiance (http://radsite.lbl.gov/radiance)
- Arnold (http://www.solidangle.com)
- V-Ray (http://www.chaosgroup.com)
- Maxwell (http://maxwellrender.com)
- Indigo (http://www.indigorenderer.com)
- iray (http://www.irayrender.com)
- Luxrender (http://www.luxrender.net)
- Octane Render (http://www.refractivesoftware.com)
- and others

I will announce if those other repositories go public on http://janwalter.blogspot.co.uk/ ...

The (work in progress) images are here:

http://www.janwalter.com/RadianceVsYouN ... ameit.html

Slides can be downloaded from http://www.janwalter.com/Download/index.html (as mentioned above).

Let me know if you have other scenes (which could be used e.g. with the creative commons license) you'd like to contribute for more render tests, if you have ideas e.g. to create a forum for these tests where people can share experience independent of any particular renderer ...

As I said, if you want access to the scenes, would like to help with future tests etc. ... my email is mentioned above. Don't get angry if I don't answer immediately. I do all of this in my spare time (therefore NO production scenes from my side) and I'm sometimes quiet busy with some commercial work

Cheers,

Jan

[A-man]

I am very intrigued by Arnold Render. I've heard it is the fastest raytracer in the world but as you said, it's not released, so it's hard to quantify that. Is it going to be open source? Or free to use? I really know nothing about it other than rumors

And just out of curiosity, what is an ASS file (I'm guessing Arnold scene file?)

Anyways, very interesting stuff!

[wahn]

I don't think it will be open source (actually I'm pretty sure it will not), but if you can do with a watermark I think it might be free to use (and you can develop shaders without a commercial license). Anyway, I'm probably the wrong person to ask ...

But my Blender exporter will be open source, so if anybody wants to modify it or contribute to it ... feel free. I'm actually planning on an exporter which can do simultaneously exports to several renderers (without the need for using renderer specific attributes/materials/etc., but react on those if there is a need). The emphasis is on comparisons (for me), not to make anything production ready (which someone else could easily contribute, but it's too time consuming for me alone).

Anyway, yes, a ASS file is the scene description and the renderer is called kick ...

[A-man]

Anyway, yes, a ASS file is the scene description and the renderer is called kick ...

I'd think with your avatar it would be called 'Bite my shiny metal'

A renderer independent exporter would be very cool. It also would be a lot of work. I can see issues with incompatibilities between renderers, but case-specific workarounds could be implemented I suppose. Free shader development would also be cool.

[jeanphi]

Hi,

Interestingproject. However I see quite a lot of issues to get something accurate: glossiness seems to be wildly different between renderers, ditto for surface albedo, do you use official exporters for each project or your own custom one? Have you checked gamma correction handling?
Out of curiosity, what LuxRender version have you used?

Jeanphi

[wahn]

Hi Jeanphi,

you are right. Glossiness is very different for those renderers and I didn't pay too much attention to get them similar. Sometimes I write my own importers/exporters, sometimes I just use an already existing ones (which probably change over time as well, e.g. Blender 2.49 vs. later ones). At the Filmakademie I used a Radiance importer (for Blender) which I wrote myself, and exporter to a RenderMan compatible renderer (3Delight) and Arnold, which I also developed from scratch, but they are far from production ready. I also have exporters for mental ray and iray which I adjust to my own needs. The point was more to keep for examples the primitives (Radiance has generators which use a lot of spheres, cones, cylinders etc.) if a renderer supports them, and to import the material settings in a way, that I do not have to adjust them for each renderer individually, but rather read values, store them somehow in Blender, and detect simple things (e.g. glass/dielectric like materials etc.) without having to define renderer specific materials (just use whatever can be used in an automatic way). For other renderers I did have to import the geometry and mess with renderer specific materials and exporters (which is probably why the images look very different, because I didn't invest too much time in that part). I got plenty of ideas for writing exporters, which are just hard to play with for most commercial packages, and I'm planning on giving other workshops at the Filmakademie about plugin development etc.

Yes, I did check gamma handling, but as I said, I really didn't pay too much attention (yet) to make those image look good, just get some results and try to make others interested in helping make those images step by step look more similar to each other. I did use LuxRender 0.8 for most of the time, but recently switched to RC1 (but haven't updated the images).

Jan