V-Ray 2.0: VRayBPTracer

[anchovy]

Chris-

Thanks for giving that a try. Its good to see where the limitations are.

-Michael

[anchovy]

Vlado-

Any new tests in this area?

Thanks

-Michael

[vlado]

We've been working on getting distributed rendering and the VRayLightSelect elements to work properly for the time being; after this is done, we will look into noise reduction techniques.

Best regards,
Vlado

[anchovy]

Cool, thanks for the update!

-Michael

[Midiaeffects]

Hey Vlado, and what about an Stochastic Progressive Photon Mapping? Did you have a look at that? Because AFAIK it's the most powerful method for difficult light interactions with lots of caustics. I wonder how it performs compared to a BPT in overall cases.

http://graphics.ucsd.edu/~toshiya/sppm.pdf
http://ompf.org/forum/viewtopic.php?...1492&start=150
http://ompf.org/forum/viewtopic.php?f=3&t=1071

Regards,
eugenio jr.

[vlado]

It's not a bad technique, but (like all photon-mapping approaches) it may be hard to apply it for large exterior scenes as occur often in architectural visualizations. Ideally some combination of this and regular path tracing could work fairly well, but I haven't seen this implemented anywhere.

Best regards,
Vlado

[prorender]

Hi vlado,

below you said that it is not possible distributing ppt. I did some tests by simply tiling the frame buffer in regions. The result is that when you put the tiled images togehter you get a full and nice rendering whithout artefacts. Now you could develop a simple script to distribute this workflow over several render nodes. Also for the calculation of light cache this workflow should work.

Can you please explain the difference between ppt and bdt? How to setup bdt in vray?

Regards
Daniel Krüger

CEO / prorender
renderfarm & render service
renderfarm rental
www.prorender.de

[sandykoufax]

hmm maybe like this?
http://www.blendernation.com/2010/07...h-blender-2-5/

[prorender]

Hi,

I watched the video but I don't know how the software works.

But my idea is only automating a simple workflow. For example you have 4 render nodes and want to render distributed. The easiest way to do this is to tile the framebuffer manually in 4 regions and render every part on a single render node. Finally you put the 4 tiles together to the desired image.

I made tests and it should work properly whithout having artefacts in the image. And now you only need a programmer who can automate the process by a script. And that should be all.

Also it were interesting to know if this workflow works for calculating the light cache in distributed way. Here you would need a tool to merge the light cache regions together. Perhaps vlado can say something about this.

Regards
Daniel Krüger

CEO / prorender
renderfarm & render service
renderfarm rental
www.prorender.de

[anchovy]

Daniel-

Would you be willing to post a sample scene of the workflow?

Thanks

-Michael

[prorender]

Dear vray users,

here I made a manual how to setup vray for a distributed ppt workflow using a renderfarm.



Another idea is to use same workflow to calculate the light cache and merge the parts together. At the moment it is not possible to let participate a renderfarm on light cache calculations.

Regards
Daniel Krüger

CEO / prorender
renderfarm & render service
renderfarm rental
www.prorender.de

[anchovy]

Vlado-

Looking at Daniel's experiment and some of my testing it begs the question what actually happening when you do a region render or a reduced resolution? If you use the full 65000 subdivs for the region why does the computation vary based on the size of the region. On an 800x600 sized image it might take hours for the full # of possible samples vs a small region, say 32x32 where it only takes 1min. Im sure there are other issues at hand but it seems like if I were willing to set up a distributed render it might take less time for much higher subdivs. Sorry to ask such I naive question but out of pure curiosity, Id love to know whats going on under the hood.

Thanks!

-Michael

[prorender]

Hi Michael,

my workflow shows that you can distribute ppt on a renderfarm. The advantage is that you can speed up the rendering. With PPT you get unbiased results nice caustics with minimal setup of settings of vray. Only the render time is high to produce noise free results. Therefore you can distribute a still image like I showed you in my workflow. You can also try to reduce the noise in post processing.

After checking the procedures once again you only have to activate "split scan lines" option and define the number of stripes in backburner settings and then the workflow is automated. For your quality settings just define some renderpresets and save them.

Regards
Daniel Krüger

CEO / prorender
renderfarm & render service
renderfarm rental
www.prorender.de

[anchovy]

Vlado-

Any thoughts?

-Michael

[anchovy]

Vlado-

Any more playing with the bidirectional path tracing?

Thanks

-Michael