GPU benchmarks

[vlado]

Please see attached scene 2012 max. It appears the lights render with artifacts when they are of a really small scale.

This is somewhat expected; the GPU code is single precision only (compared to selective double precision for V-Ray and V-Ray RT CPU). For this particular scene though, we might be able to fix it.

Also Im not sure why but I thought that caustics used to work in rt gpu? In my test however I can't get any caustics in the refraction, works with cpu rt though.

Hm, this works fine in my tests - just today rendered a few scenes with caustics on the GPU. However the scene scale might have something to do with it. Also, larger area lights typically work better than a direct light (if that's what you are using) or a small area light.

Best regards,
Vlado

[Morbid Angel]

Hi Tashko,

I think it was fixed in the newest build, it works as expected now, but I found another problem. Please see attached scene 2012 max. It appears the lights render with artifacts when they are of a really small scale.

vrayrt_gpu_smallLightBug.zip

Also Im not sure why but I thought that caustics used to work in rt gpu? In my test however I can't get any caustics in the refraction, works with cpu rt though.

[tashko.zashev]

Hi Dmitry,

Can you post your test scene here, so we will try it with your setup in our environment?

[Alan Iglesias]

While it appears that glossy refraction works, I am not positive as to what is happening, it seems rt gpu does not trace more then default number of depths, even though I specified 20/20
here is 3 renders with glass sphere and glossy refraction of .5.

Yeah, maybe they still need to turn on > default depth...

-Alan

[Morbid Angel]

I have, its not working correctly. The latest nightly now has all of 3 - now the sphere renders really black...

[matanov]

While it appears that glossy refraction works, I am not positive as to what is happening, it seems rt gpu does not trace more then default number of depths, even though I specified 20/20
here is 3 renders with glass sphere and glossy refraction of .5.

regular vray

[ATTACH=CONFIG]11776[/ATTACH]

rt CPU

[ATTACH=CONFIG]11777[/ATTACH]

RT GPU CUDa

GI/Trace depth 20/20

[ATTACH=CONFIG]11778[/ATTACH]

Try the same thing with a latest night build.

Gradient settings

Use Gradient ramp, I think Gradient is not implemented yet in GPU.

[Morbid Angel]

Just a quick clarification that Glossy Refraction is very much alive and well in RT/GPU. A really fun thing to play with in real time...

-Alan

While it appears that glossy refraction works, I am not positive as to what is happening, it seems rt gpu does not trace more then default number of depths, even though I specified 20/20
here is 3 renders with glass sphere and glossy refraction of .5.

regular vray



rt CPU



RT GPU CUDa

GI/Trace depth 20/20

[eyepiz]

Gradient settings

I cant get gradients to work in RT GPU.

I use the floor material in white to fade out the floor plane in a scene with a white background.

any suggestions?

Thanks,

[vlado]

Which mode of the falloff map are you using?

Best regards,
Vlado

[eyepiz]

I cant get gradients to work in RT GPU.

I use the floor material in white to fade out the floor plane in a scene with a white background.

any suggestions?

Thanks,

Gradients and falloffs have been supported since a long time, even in the official builds. Now we have also added support for Color Correction and Mix maps.

Best regards,
Vlado

[vlado]

-rtEngine, there is a way to choose 0/1 or 3, which I assume mean 0 - regular rendering, 1 - rt cpu, then 3 - rt gpu open cl, so what would be the option for rt gpu cuda, when I try -rtEngine=4, it crashes with errors

-rtengine=5 specifies the CUDA engine.

- is there a way to display rt gpu statistics in standalone? what would be the command for that?

No way to do that for the present. Some statistics will be printed at the end of the render.

- is there a way to set max sampling level before it will stop? I tried -rtSampleLevel=512 but it continued rendering past that?

Works for me...

Best regards,
Vlado

[Alan Iglesias]

...it has a glossy refraction which obviously is not yet supported by gpu...

Just a quick clarification that Glossy Refraction is very much alive and well in RT/GPU. A really fun thing to play with in real time...

-Alan

[Morbid Angel]

Vlado I was trying to render this scene in standalone, and I got a few questions:

-rtEngine, there is a way to choose 0/1 or 3, which I assume mean 0 - regular rendering, 1 - rt cpu, then 3 - rt gpu open cl, so what would be the option for rt gpu cuda, when I try -rtEngine=4, it crashes with errors
- is there a way to display rt gpu statistics in standalone? what would be the command for that?
- is there a way to set max sampling level before it will stop? I tried -rtSampleLevel=512 but it continued rendering past that?

[vlado]

the way the lamp renders is weird, or em I wrong?

Yes, it has some weird material setup...

Best regards,
Vlado

[Morbid Angel]

yeah thats much better. The lamp though I think is a problem and I don't really understand what's happening...it has a glossy refraction which obviously is not yet supported by gpu, but besides that there is a light inside so shouldn't the lamp be illuminated like the the example I posted yesterday? it seems that even in regular vray, the way the lamp renders is weird, or em I wrong?