Cycles Development Updates

This patch is to render the missing tiles in say an OpenEXR file when the render task was cancelled on some server because reasons (their use case). They were also talks about having a system like Renderman’s where only a few samples of an animation are rendered for each frame so you can have a look at it and decide if you want to render more samples, if that’s what you mean, this will be done later, but I don’t know when.

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Yes, this is cool, and it is one of the points I made with the proposal that I was talking about about 10 days ago in this thread (see above).

I just tested the most recent V2.92 Alpha and I don’t see the tile stealing working either.

Hang on, let me dig deep and pull some ideas out of my rear end…

Blender could keep track of how long it takes to render the material preview scene for each material. Before the final render Cycles can fire a small number of rays into the scene and see which materials they hit. Tiles with a high score based on the materials within them get given to the GPU, the lower tiles go to the CPU, then towards the end of the render the new tile stealing feature gives more of the heaviest remaining tiles to the GPU.

I agree that it probably won’t work well with animation and that complex things in reflections make it useless. So, just put options related to this under the Performance section and let people turn them on and configure them if they know they have a situation where it will benefit them. I don’t have the hardware and patience to render animations so I’d probably be using these features all the time if I had them.

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Does anyone remember an episode of Blender Today where they mentioned a command-line command that would take an already rendered frame and “add samples to it”? It was 2 or 3 years ago I think.

In the meantime, the Blender Suspender add-on can be used: Blender Suspender.

So i just had to setup an environment with bunch of lights, areas and spot. And after some testing i found out i had to turn off multiple importance on each one of them. That reduced noise by a lot. What’s the point having that option on lights? are there any scenarios where it is useful? is this an intended behavior?

Cycles kinda has that already - at least in the viewport.

If you do a viewport render with say 10 samples, then go and change the number of samples to 15, the viewport only renders the additional 5 samples on top - it doesn’t start again from zero.

I wouldn’t imagine it’d be particularly difficult to pause a render on an arbitrary number of samples - then resume. The engine itself seems to already have this capability at it’s core.

the viewport doesn t use bucket rendering

Isn’t the viewport simply treated as one big bucket?

no, its like having the progressive refine on ( i think … )

There’s an addon “Blender pause”, which lets you to pause whole blender and dump it to tray.
I’ve used it to render big scenes overnight, pausing when getting to computer, and unpausing when going away.
Everything was fine, except of course samples per second, as of blender is just counting start time and end time timestamps, instead of effective time.

Enabling it adds that light to the list of lights that can be sampled directly. This makes sampling the light more efficient, but each sample can only pick one light, so the more lights on the list, the more noise. (branched path can sample all the lights, so more lights on this list means a slower render instead of a noisier one).

Disable it for lights that do not significantly illuminate anything that’s not right next to them. And try to limit how many total lights you have in your scene. (I’d say “limit how many lights you have MIS enabled for” but that implies you can wiggle out of this by disabling MIS on lights that would need it if not for a zillion other lights that also need it. Which doesn’t work)

EDIT: I should note that one of the GSoC projects from last year is “many light sampling” which improves performance when you have a large number of lights with MIS.

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I’m kinda disappointed that there s nothing exciting for cycles in this release for me beside the mo blur from .Abc, i hope the Bf will recruit someone to work on the long list of patches that needs to be reviewed and worked on

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Nothing is at a standstill there are many development meetings with various international collaborators, and there have also been some good updates in previous releases. I am happy with the work done.
I also want some update in other Blender parts, such as NURBS but nothing happend in 20 years


Same here. There was talk a year or so back about giving more tools for procedural material creation - and I did see some new features being worked on, but these appear to be either abandoned or have been stuck in review for a while:

Enhancements to Voronoi - abandoned :slightly_frowning_face:

Gabor Noise - Needs Review

Hex tile texture - Needs Review

SDF Nodes - Needs Review

Line Material node - Needs Review

Truchet Texture Node - Needs Review

Blue Noise dithered sobol - needs revision


if i remember correctly those are thing that will serve more the big studios/company, like the support for rt core for AMD card, cpu+gpu ( optix ) rendering etc, most of what im reading in the rendering meeting doesn’t affect me

On the other hand i can t wait for the work of kevin to be merged ( fast scene update ) hopefully it will make it for the rendering and not only for the viewport

There was also a GSOC that ended-up as improvements in 2.81, 2.82 & 2.83.

Yes. Those patches are waiting for review.
But that may be comprehensible that after reviewing Omar’s work, cycles dev were taking a break about procedural stuff.

The only patch that is tagged as abandoned is as is ; because, according to its author, it was outdated after Omar’s work.
But if you read Charlie’s last remark, it is clear that idea is not abandoned. Just the patch is.

So, Charlie’s work may end-up in Blender after restart of a cycle of priorities.
I think that Add Line material node will probably enter into competition with lanpr or be part of future Viewport Compositor’s work.

That is easy to pick your 7 favorite patches.
But developers have continuously to think about integration of almost one hundred of patches waiting for reviews, just for Cycles.

2.91 is a poor release in terms of Cycles features. Since Cycles integration in 2.61, it is the first and unique release without a section of release notes dedicated to Cycles.
But there is already a Cycles section in release notes of 2.92.


Cycles should be seriously strengthened…


I’m pretty happy with Cycles as it is right now. Unpopular opinion, I know :man_shrugging: