Gpu Rendering question

[jkontiola]

I have MD Radeon R9 M290X GPU. I thought it was Opencl gpu.

When I activate Vray Rt Gpu Opencl rendering It renders just some small area of different color pixels.
When I render with CUDA it renders the real image.

Weird?

[savage309]

What OS and drivers are you using and do you have the log of the render ?
I believe that when you check CUDA, V-Ray fallbacks to RT CPU rendering. For the OpenCL it is better to check the V-Ray log first.

[jkontiola]

How do I check the Vray log?

[jkontiola]

Still the same problem exist. I have Mac Os Sierra. VRAY RT not working. Is it supposed to work well? Or is there still many issues remaining? Should i still just continue basic cpu rendering?

[andybot_cg]

openCL doesn't work very well. I tried it some time ago and it was kind of like what you describe. I use CUDA just fine with a GTX 1070, though there are still a lot of things that are not supported (for example layered materials don't seem to work.) Unless you have a decent card with CUDA support, then yes, it's best to stick to CPU.

Andy

[jkontiola]

Thanks for your answer. Are you able to render final quality image with CUDA faster than with CPU?

[andybot_cg]

Yes, I find CUDA faster on a single machine than CPU, but I find most materials even moderately complex don't render the same. Another example is bump mapping doesn't seem to work currently in GPU.

[savage309]

Yes, I find CUDA faster on a single machine than CPU, but I find most materials even moderately complex don't render the same. Another example is bump mapping doesn't seem to work currently in GPU.

The CPU & the GPU are different engines, so some differences could be normal (for example the bump is handled differently in the GPU engine). If there are quite a lot difference, please send them over and we look at those.

Best,
Blago.

[andybot_cg]

Thanks Blago. I guess I should start a new thread with examples of problems I've encountered with GPU rendering of materials.

[savage309]

Thanks Blago. I guess I should start a new thread with examples of problems I've encountered with GPU rendering of materials.

We have fixed a bunch of such issues recently, so will be glad to see if those are being solved.
You can send material samples to blagovest.taskov@chaosgroup.com directly as well.

Thanks,
Blago.

[andybot_cg]

Just sent a file with some test materials with example of the two problems I described.

[jkontiola]

Any idea if the OpenCL GPU rendering gonna work anytime soon?

[savage309]

Any idea if the OpenCL GPU rendering gonna work anytime soon?

On what hardware and OS ?
It should work fine on AMD GPUs on Windows.

[jkontiola]

iMac late 2014 with Sierra OSX
ATI Radeon R9 M290X GPU

Vray RT opencl starts to render the image and everything seems to be fine. Render looks normal at start. When render is finished the image changes to black.

[savage309]

iMac late 2014 with Sierra OSX
ATI Radeon R9 M290X GPU

Vray RT opencl starts to render the image and everything seems to be fine. Render looks normal at start. When render is finished the image changes to black.

This is very interesting, thanks for the update !
The OpenCL compiler is much better in Sierra, but we still don't support OpenCL officially on macOS.

Best,
Blago.