CPU-based Interactive Denoising for Non-GPU users

[Md_Minhajur_Rahman_F]

Hi everyone,
​I’ve been using Corona Renderer for a while and I absolutely love the workflow and output quality. However, I’ve been facing a limitation regarding Interactive Rendering that I wanted to bring to the developers’ attention.
​The Issue:
Currently, the interactive denoising feature seems heavily dependent on GPU support. While this is great for those with high-end graphics cards, many of us—especially students and freelancers—use mid-range builds (e.g., Ryzen 5 5600G or mid-tier Core i5 setups) that rely more on CPU power than dedicated high-end GPUs.
​The Request:
Would it be possible to introduce a CPU-based Interactive Denoiser for Corona? Having something similar to V-Ray’s approach—which works efficiently on CPUs—would be a massive help for those of us who don’t have powerful GPUs but have capable CPUs.
​Why it matters:
​It would drastically improve the workflow for texture/roughness/lighting previews without needing expensive hardware.
​It makes Corona more accessible for students who are just starting out.
​I’m curious if the dev team has any plans to include this in future updates. Also, I’d love to hear from other users if you are facing the same limitation!
​Looking forward to your thoughts.
​Thanks!

[AramAvetisyan]

Hi,

You can use Intel (OIDN) denoiser and it will automatically select which hardware to use to denoising (it will pick the faster option).
You can manually set the OIDN backend in development settings as well.

Check this thread for more info:

Select GPU for Intel Denoiser?

I’ve tried searching but couldn’t find anything. Is there any way to tell Corona’s Intel denoiser to use the integrated GPU instead of the main GPU? Or to force it to use CPU only even with a capable GPU present? I’ve tried OIDN environment variables but I guess Corona’s implementation ignores them. Thankful for any info.

[maru]

Currently, for interactive rendering, you can only use the NVIDIA or Intel denoiser in GPU mode and both require an NVIDIA GPU.

For production rendering, you can use the Intel denoiser or Corona denoiser, even if you don’t have an NVIDIA GPU. To make sure the Intel denoiser uses CPU only, you need to open the development/experimental stuff rollout and specify the backend there.

@Md_Minhajur_Rahman_F

Having something similar to V-Ray’s approach—which works efficiently on CPUs—would be a massive help for those of us who don’t have powerful GPUs but have capable CPUs.

Please note that both the NVIDIA and Intel denoisers usually need less than 1 second to denoise the image, even on a low-end NVIDIA GPU.