What are the plans for patch review for Cycles?

Hi there @brecht

I’m wondering, since in 2.81 optix has been implemented, what are the plans for Cycles patch reviews?

I wonder this because right now Cycles is much more slower than what it can be, there are several patches to be reviewed and they work very well in conjunction (I know you laready know that), and in 2.81 there was nothing on this regard.

Also, do you have something new in the pocket for render optimization fopr 2.82? I mean something more apart from the patches already out there.

We need more speed for render and also better RAM management, because a scene that can be rendered with 8 Gb in the GPU should not need 25Gb in the CPU, or at least a way to free up all the blender used RAM when everything is already on render.

The latest case for us was a scene that needed between 12 to 18Gb of ram (depending on several things enabled/disabled) but Blender needed near the 64Gb of ram to be able to render that scene, I imagine that if a GPU can render it with 12Gb, the CPU is also capable of doing it, and if the culptrip is Blender that keeps a lot of useless data in memory, maybe there is a way to free up all that memory from RAM, so systems with 32Gb of ram are capable of rendering a scene that they should be capable to render without having to use swap.

OK, this was a little baby rant (without acrimony or anything… just wanted to tell you the case :slight_smile: ) because I had to fight with these problems to render our latest project, but “rants” apart, what are the plans for Cycles and 2.82? Will we see improvements and reviewed patches?


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Sounds like the question is rather about new development rather than patch review, unless there are patches that address all these issues that are just sitting in the tracker waiting for review?

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well yes and no :slight_smile:

It’s more like an open question, it’s more about what are the near future plans for cycles, both regarding patch review status and new developments, and I just told a recent case I had to fight with, but I know development may not go in that direction, I was just exposing a problem, but I could have talked about how scramble distance and blue noise dithering are helping us, but we need more speed, and not just in GPU zone, but also in CPU because 8Gb of ram are good but not enough in many cases in complex scenes.

So I don’t want to write a super long post again, to clarify things, it’s a question about the near future of Cycles for 2.82 :slight_smile:


You can find the roadmap for cycles here .

Oh, I know that list, but that’s the same we had for 2.81, that’s why I’m asking about what are the actual plans for 2.82, I see that more as a “possible future plans”, but nothing clear, of that list the only thing that was implemented in 2.81 is optix (also the nodes, but they were added after some of those points were already in the list, and they were not a red point)

So the question is what is the plan of action regarding those points or other possible improvements that are not listed there.

EDIT: 2.81 also includes OpenImageDenoise, I forgot that :slight_smile:

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The list can be also considered the action plan. We’ll see how things pan out.

The answers feel like there is nothing clear to speak about, maybe is too soon in 2.82, but since the “new features” spot time is small, I wanted to ask about this.

I hope some improvements can already be applied to get a proper performance gain, the hopes were put in 2.81, but it seems optix took nearly all the cycles core devs development and review time and it’s a pity, but on the other hand it was something important to implement so other things can be implemented also with optix in mind.

I apply the patches to our own build and I have no problem with that, but I know that not many people uses custom builds (because of fear or because they don’t know the builds or any other things), and it’s tedious to see how people feel like cycles is a slow render engine when in fact is quite fast, and it can be even faster, I’m sure Brecht has some ideas and possible optimizations in his mind, but it needs some modernization, right now in master is several times slower than what it can be and it’s a true pity that many people cannot leverage cycles at it’s full potential :slight_smile:

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