Cycles Development Updates

I’m using Cycles-X for a personal test project (archiv exterior and interior).
One of the rooms I’ve is with a big frosted glass on one side and two door-windows on the opposite side.
The lighting I’ve choosen for the whole scene put light inside this room just as indirect lighting.
Well, I can’t clean this. I’m trying everything (except denoising i don’t like) but with no luck.
I’m using a GTX1070 (not super fast card nowadays) but with 5000 samples I can’t clean and still noisy.
I hope they’ll introduce some caching system or something new that face these scenarios.

said this, I have to make my compliments for the update, comparing with 2.9x Cycles it seems clearly a great step.
Go on devs and show us the next features!

oh ok i had no idea.
so whats a good workflow? I usually render 4K images. should i put it at default 2048, or should i put it higher 4096?

Depending on your GPU and the complexity of the scene you want to render you can even try disabling the tiling completely.
Just try rendering the same image a few times with different settings. I guess that even 2048px isn’t too small of a tile size to cause any negative effects on render time but your mileage may vary.

Are your lighting the room through the glass? So that the only light in the room is “caustics”?
Then noise is more than expected

Yes, actually yes.
This room borders with the living room where the sunlight enters…so actually the light is coming from the frosted glass is indirect light of the living room.
I know that it’s not the best scenario, probably I have to use some area lights to fake this incoming indirect light but I’d like to avoid this kind of setup.

You could make the frosted glass emissive - it makes surprisingly little difference to the look of the scene, but increases render times significantly.

I’ll try your suggestion. thank you

Yes, and on top of that example: you can also use a Lightpath node and bound the emission shader just to diffuse paths, so that everything else, included reflections, work just as a frosted glass.
Just make sure you’re emitting only in one direction :wink:


Thank you for your suggestion, it seems working and helping a bit.

Exactly. Tile rendering preserve from oom. Progressive, will be used for fast feedback on a “global”/“full frame” render.
With dimensions reduced if not enough memory.

It seems on optix side all issues i mentioned have been solved. just bravo! All tests have been done on a scene with different materials including sss and fur.

here are some rendertimes

transform, optix - 11 sec
transform, cuda - 19 sec

deformation, optix - 14 sec
deformation, cuda - estimated 1+ hour
deformation, no fur, cuda - 51 sec

I hope cuda side will see some development as well, as render with deformation motion blur could not render at all until i disabled fur. Either way, big thanks to Devs!


Sad news for Cycles development

William will not be continuing as part of the Cycles team at the Blender Institute. Many thanks for his contributions to the project, and all the best for the future. We are looking into hiring another Cycles developer.

Thank you William for your work!


that’s a bummer

That’s a shame. What was he working on?

Afaik he worked a lot on sampling integrator, scrambling distance and the like.
Sad he goes, but hey, they’re hiring again…
“A new hope”

If im not mistaken you need that glass to use fake shadows or only caustic rays will get through into the room. Theres a hack in cycles where you use a mix shader node with your glass node, and mix it with a transparent node, then use the “is shadow ray” from the light path node as the mix factor.

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@lukasstockner97 as I remember previous time you’ve been occupied by university - has anything change? You’ve been one of the most active (and still) contributor (NLM was groundbreaking!), knowing well Blender and Cycles code. Do you still consider joining Blender Institute?

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Farewell to William, and thanks for the contributions.

It took more time to choose than the time he worked, and I think he worked remotely.
It doesn’t have to be an easy job and it won’t be easy to find someone.

Very interesting wording. Seems like he was let go rather than he left Blender Foundation.

Anyone knows why he is no longer part of BF?