Blender Git Loki

Fix tile size calculation in Cycles X

Was not behaving correct when number of samples is way above
number of available path states.

Reported by Alaska in the Cycles room in the blender.chat.

Cleanup: Spelling in Cycles X comments

Cycles-X: Change viewport update system to be time based rather than sample based on fast devices

The viewport update speed when rendering with infinite samples has been changed to work based primarily on time since render start rather than sample count.

This change has been made because if you have a device fast enough to exceed 32 samples in 0.1 seconds, then the next viewport update you'll observe is 2 seconds after `render start` which can be annoying for anyone wishing to quickly iterate on fine details as `render start` is usually a 1 sample per pixel image meaning fine detail is lost in noise or overly blurred by a denoiser.

This change was made possible with help from Will Rusthon (a friend) and Blender developers.

Here is an example video of the issue (some of the "viewport changes" you see are due to compression artifacts to keep the video small):
{F10290321}

And here is my fix tested (the second demo with the caustics is there to show that the viewport updates reduce as time goes on. It's easier to see in the caustics scene due to the fireflies. This is important because reduced viewpoint updates means faster ray tracing. The difference is that with this patch the slow viewport update (once every 2 seconds) has been moved to after rendering for 8 seconds rather than occurring at 32 samples which could happen really quickly with simplistic scenes. Also the denoiser stopping at the end of the video has been fixed and is currently in the patch available for review):
{F10290508}

Reviewed By: sergey, leesonw

Differential Revision: https://developer.blender.org/D12265

Merge branch 'master' into cycles-x

Cycles X: Remove tile, FSAA, and save buffers options

FSAA setting was not used by any engine.

The Save Buffers is being replaced with the new tile rendering
in Cycles.

Removing code from Blender side because there is no way we can
guarantee it is working,

Unfortunately, non-official external render engines need to
implement those options on their side. But good news is that
they have more control this way.

Differential Revision: https://developer.blender.org/D12323

Merge branch 'master' into cycles-x

Cleanup: clarify code comments, use same logic for future GPU device

Cycles X: some refinements for the make new Random Walk mode

* Make scattering radius more similar to the old one, for easier comparison
between modes and converting existing files.
* Change default subsurface mode to Random Walk in startup file.
* Fix incorrect clamping in OSL closure.

Fix crash cancelling render in middle of scene update

Particularly likely with preview renders. Detect cancel state after
scene update rather than using incomplete scene for render.

Remove accurate cryptomatte implementation

Affects both Cycles and EEVEE.

The motivation:

- For EEVEE it is a performance penalty to do GPU transfers for every
sample rendered.

- With big tile rendering in Cycles the accurate mode can have a very
high memory footprint.

- Feature parity between CPU and GPU: the GPU code paths should provide
results which are usable by production.

If there are cases when the accurate is really a must-have we'd need to
have a demo file and investigate how it can be supported on both CPU
and GPU.

Note that for comparison of accurate vs. non-accurate in the regular
Cycles should be done very carefully: CPU does not implement sorting
for non-accurate mode, so doesn't OptiX; and GPU does not support
accurate modes; CUDA doesn't implement sorting properly when adaptive
sampling is involved (what a mess!).

Differential Revision: https://developer.blender.org/D11975

Cleanup: Spelling in variable name

Cycles X: change subsurface anisotropy range to 0..1

Negative values don't work well, don't support them for now.

Merge branch 'master' into cycles-x

Cycles X: Make path util aware of session temporary directory

Will allow to sore session-specific data, such as partial tile file.

This is a more re-usable case of the way how OSL compilation is done:
the OSL compilation creates temp file from Python and passes it to
Cycles.

Differential Revision: https://developer.blender.org/D12279

Cleanup: Remove unused render settings

Debug pass type is a residue from the original debug passes support
in Cycles. It got re-implemented using runtime passes registration.

Start resolution was used by Cycles ands Blender Internal. Cycles
calculates it automatically, and Blender Internal is no longer with
us. Render engines which still needs such option can register it as
a custom property.

Differential Revision: https://developer.blender.org/D12280

Merge branch 'master' into cycles-x

Cycles X: Fix crash with Subsurface Scatter GLSL shader after anisotropic commit.

7811c1147230 reintroduced paramaters that were removed in 9187156ab65c.

Cycles X: Fix some typos in code comments.

Thanks to Alaska for finding these.

Cycles X: Clarify comment in the GPU graphics interop

The graphics interop is disabled in the multi-device rendering, so
there is no need to apply slice offset in the film convert.

Merge branch 'master' into cycles-x