Hybrid rendering causing different results

[tegan_pearce]

Hello,

Please take note I am a graphic designer, not a 3D artist. I am fairly new to the world of 3d modelling and rendering, so please bare with me.
My workplace has recently purchased a new computer specifically for 3d purposes. We have been trying to set it up so we can use the hybrid method of rendering, using both the CPU and GPU for faster results.

Without changing anything except render settings, switching from CPU to hybrid (ignore the change in camera angle, I am aware that the back light is hitting differently due to this), my render looks completely different. The colours and lighting are off, making the scene a yellow-green instead of blue, and the render warning I am getting is in regards to Adaptive Lighting.
I'm not sure what this is and how to change it? Would that be what's causing the change?

Is there something I need to change other than the render settings when switching from CPU only to CPU & GPU rendering?

Thank you,
Tegan

[nikoleta.garkova]

Hi tegan_pearce

It is worth to note that GPU/Hybrid is different engine than the CPU, so it is expected to have slightly different results. This is why it is advisable to stick to the one of the two engines. For example, always use CPU or always use CUDA/Hybrid. If you stick to CUDA/Hybrid, you will be able to utilize both your CPUs and GPUs.

That being said, such a drastic change in lighting seems a bit odd - would it be possible to let us know what changes have you made in the Render Settings and what is the exact warning you are getting in the V-Ray log? It may be that some of the features you are using are not supported on GPU - you may have a look at our list of supported features here: https://docs.chaosgroup.com/display/...orted+Features

You could also forward us the project file (with all its assets) through our contact form so we can have a look and test it here. Please share the exact version of V-Ray along with the host application used, and make sure to mention this thread in the email.

[tegan_pearce]

Thanks nikoleta.garkova for your response.
I have been doing a bit more reading, and yes, I was unaware that GPU was a different engine (I don't know a huge amount about computers tbh!), so that does explain why I am getting a different result.

The only thing I have changed in the settings was the renderer (V-Ray GPU 5, hotfix 2), and then selecting CUDA engine type from the Perf. tab. I made sure to tick C++ and NVIDIA. I did this by following the help guide here.

Would that mean when rendering with GPU/Hybrid that my colours will be out? Because the CPU colours are accurate to what I chose with the colour picker.

I have tried to submit my project but I cant seem to get it within the file size limit! I have tried to archive it, but its just under 1GB.

Thank you,
Tegan

[nikoleta.garkova]

Hi tegan_pearce

I'd say such a discrepancy is not expected if you haven't made any significant changes in the settings, so best would be to troubleshoot the project.
You pack the files and use any file-sharing platform of your choice (e.g. WeTransfer, Google Drive) and forward us the transfer link - as mentioned, you can reach us through our contact form, and make sure to mention this thread in the email. Thanks!