Exclude objects from denoising

is it possible to exclude some objects from denoising?
thanks ,

Hi @lopez,

What you can do is render a de-noised and noisy image, as well as a clown pass. You can then use an image editing software to composite all three images. The noisy image should be overlayed over the de-noised one. It doesn’t matter where you put the clown pass, since it will be turned off later, but it lets you select individual objects to mask most of the objects in the noisy render, but leave other once exposed.

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thank you very much for your reply. To me is crazy to work like this…I would like to have an option to do this because when I render the tress the denoising create artefacts…

Denoising works on the whole image, one can’t exclude objects from that in a single render in our render tools.

Hi @nathanletwory
Keyshot has the option to blend the denoised and the original render, letting you fade between the two and find the best balance between the noisy original and the denoised version. Maybe something like that would be a possible solition at some point?

That sounds like composting. Automated approach of what @diffarch suggested.

Adding composting tools would be great. I’d like to keep such features separate from rendering. With all these end-result-in-one-go makes the rendering more complicated than it should be - leave postpro to separate tools.

I wouldn’t mind having those tools in Rhino, mind you. Just not handled in the Rendering step.


Sure - was thinking it as an addition to the post-panel!

Is there a way to render a clown pass in Rhino Cycles? Would be a neat feature. ^^

To be honest I don’t know what a clown pass is. Is it a mask pass? If yes then yes, it would be possible, but there is jo GUI for that yet.

A clown pass is usually a rendering where each individual geometry object or material in the scene is displayed with a flat color, so that you can for instance make selections by color in post-processing and create masks from these selections.


Possibly, although I don’t know what a “mask pass” is. :wink:

It would be really, really, really, really neat to have that as a GUI-promoted feature!! :smiley:

Must say I haven’t heard the term clown pass before. But (random) color pass should eventually be possible - Cycles we use anyway.

Is that a screenshot of your own work, btw?

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No. :sweat_smile:

Ok, I was secretly hoping you’d be under-cover Jonathan Ball / Pokedstudio, as that screenshot looks to be his work. (:


I should have been more thorough and given credit, where it was due. It was honestly simply one of the first images that came up, when I searched for “clown pass”. :wink:

Wow, this is mesmerizing stuff! Great imagery!! :fire:
Thanks for sharing.

By the way, the term “clown pass” is for instance used in Keyshot:
Screenshot 2021-01-18 at 07.51.43

Do you think this would be feasible in Python/GHPython, meaning firing up Cycles and rendering flat objects with random colors?

Right now, even with Grasshopper, it is not possible to set up render layers. But in the future I hope we can hook up render layers and more, if not all, of the Cycles shader nodes.

Right, I don’t know Keyshot or any of the other rendering solutions - just Cycles.

And then still one would need to composite the final results. The compositing part I’d like to keep out of the actual rendering as a separate solution. Easiest would be to at least have multilayer exr saving possible.

Uuh, nice! :smiley:

When I look at Blender today, it really seems to be all you need (except for Rhino for N.u.r.b.s.).

Yes, that’s totally reasonable. For me it’s not even necessary to have compositing tools in Rhino per se. I’d rather be interested in bumping up the feature set of Cycles, with for instance different, default render passes that then make compositing easier.
Multi-layer EXR saving sounds a-m-a-z-i-n-g!