This patch implements blue-noise dithered sampling as described by Nathan Vegdahl (https://psychopath.io/post/2022_07_24_owen_scrambling_based_dithered_blue_noise_sampling), which in turn is based on "Screen-Space Blue-Noise Diffusion of Monte Carlo Sampling Error via Hierarchical Ordering of Pixels"(https://repository.kaust.edu.sa/items/1269ae24-2596-400b-a839-e54486033a93).
The basic idea is simple: Instead of generating independent sequences for each pixel by scrambling them, we use a single sequence for the entire image, with each pixel getting one chunk of the samples. The ordering across pixels is determined by hierarchical scrambling of the pixel's position along a space-filling curve, which ends up being pretty much the same operation as already used for the underlying sequence.
This results in a more high-frequency noise distribution, which appears smoother despite not being less noisy overall.
The main limitation at the moment is that the improvement is only clear if the full sample amount is used per pixel, so interactive preview rendering and adaptive sampling will not receive the benefit. One exception to this is that when using the new "Automatic" setting, the first sample in interactive rendering will also be blue-noise-distributed.
The sampling mode option is now exposed in the UI, with the three options being Blue Noise (the new mode), Classic (the previous Tabulated Sobol method) and the new default, Automatic (blue noise, with the additional property of ensuring the first sample is also blue-noise-distributed in interactive rendering). When debug mode is enabled, additional options appear, such as Sobol-Burley.
Note that the scrambling distance option is not compatible with the blue-noise pattern.
Pull Request: https://projects.blender.org/blender/blender/pulls/118479
The first two dimensions of scrambled, shuffled Sobol and shuffled PMJ02 are
equivalent, so this makes no real difference for the first two dimensions.
But Sobol allows us to naturally extend to more dimensions.
Pretabulated Sobol is now always used, and the sampling pattern settings is now
only available as a debug option.
This in turn allows the following two things (also implemented):
* Use proper 3D samples for combined lens + motion blur sampling. This
notably reduces the noise on objects that are simultaneously out-of-focus
and motion blurred.
* Use proper 3D samples for combined light selection + light sampling.
Cycles was already doing something clever here with 2D samples, but using
3D samples is more straightforward and avoids overloading one of the
dimensions.
In the future this will also allow for proper sampling of e.g. volumetric
light sources and other things that may need three or four dimensions.
Differential Revision: https://developer.blender.org/D16443
While it helps on many scenes, it can be disruptive for existing scenes and
for benchmarks the differences in timing can be confusing. So be a bit more
conservative and only it enable it for new scenes.
Materials now have an enum to set the emission sampling method, to be
either None, Auto, Front, Back or Front & Back. This replace the
previous "Multiple Importance Sample" option.
Auto is the new default, and uses a heuristic to estimate the emitted
light intensity to determine of the mesh should be considered as a light
for sampling. Shaders sometimes have a bit of emission but treating them
as a light source is not worth the memory/performance overhead.
The Front/Back settings are not important yet, but will help when a
light tree is added. In that case setting emission to Front only on
closed meshes can help ignore emission from inside the mesh interior that
does not contribute anything.
Includes contributions by Brecht Van Lommel and Alaska.
Ref T77889
It can be assumed that all scripts comply with basic pep8 formatting
regarding white-space, indentation etc.
Also remove note in best practices page & update `tests/python/pep8.py`.
If we want to exclude some scripts from make format,
this can be done by adding them to `ignore_files` in:
source/tools/utils_maintenance/autopep8_format_paths.py
Or using `# nopep8` for to ignore for individual lines.
Ref T98554
* Replace license text in headers with SPDX identifiers.
* Remove specific license info from outdated readme.txt, instead leave details
to the source files.
* Add list of SPDX license identifiers used, and corresponding license texts.
* Update copyright dates while we're at it.
Ref D14069, T95597
This includes much improved GPU rendering performance, viewport interactivity,
new shadow catcher, revamped sampling settings, subsurface scattering anisotropy,
new GPU volume sampling, improved PMJ sampling pattern, and more.
Some features have also been removed or changed, breaking backwards compatibility.
Including the removal of the OpenCL backend, for which alternatives are under
development.
Release notes and code docs:
https://wiki.blender.org/wiki/Reference/Release_Notes/3.0/Cycleshttps://wiki.blender.org/wiki/Source/Render/Cycles
Credits:
* Sergey Sharybin
* Brecht Van Lommel
* Patrick Mours (OptiX backend)
* Christophe Hery (subsurface scattering anisotropy)
* William Leeson (PMJ sampling pattern)
* Alaska (various fixes and tweaks)
* Thomas Dinges (various fixes)
For the full commit history, see the cycles-x branch. This squashes together
all the changes since intermediate changes would often fail building or tests.
Ref T87839, T87837, T87836
Fixes T90734, T89353, T80267, T80267, T77185, T69800
* Move out of Simplify panel, into Light Paths > Fast Global Illumination
* Add separate boolan setting to enable/disable it separate from Simplify
* Default AO bounces to 1
* Put ambient occlusion distance in this panel as well
Support Python 3.10a5 or 3.9x with support explicitly enabled.
- Enable Python's postponed annotations for Blender's RNA classes
types registered on startup.
- Using postponed annotations has implications for how they are defined,
since they must evaluate in the modules name-space instead of the
classes name-space. See changes to annotations in `release/scripts`.
- Use `from __future__ import annotations` at the top of the module
to ensure the script will run with Python 3.10.
- Old logic is kept since it could be used if PEP-649 is supported.
Resolves T83626
Ref D10474
This patch will share the AOV settings between Cycles and Eevee.
It enable using the AOV name conflict detection of Blender. This
means that unlike how Cycles used to work it isn't possible to add an
AOV with a similar name. Conflicts with internal render pass names will
be indicated with an Warning icon.
Reviewed By: Brecht van Lommel
Differential Revision: https://developer.blender.org/D9774
Blender has now the place to store the Cryptomatte settings. This patch
migrates Cycles to use the new settings.
Reviewed By: Brecht van Lommel
Differential Revision: https://developer.blender.org/D9746
This simplifies compositors setups and will be consistent with Eevee render
passes from D6331. There's a continuum between these passes and it's not clear
there is much advantage to having them available separately.
Differential Revision: https://developer.blender.org/D6848
Shader nodes are now shared with Eevee, so makes more sense to have it in
the core and not be Cycles specific.
Fix T62415: issues with append/link of old Cycles settings.
It only returned those for the active device type. For backwards compatibility
return them all again, but still avoid enumerating them from our own code on
startup or opening preferences.
The code assumed all datablocks were read from .blend files saved with the
same version. This restructures the Cycles versioning code to take into
account libraries.
Even though it makes sense logically to have displacement actually displace
the mesh, this is causing a lot of confusion for existing users that are used
to the previous behavior. Further, since Eevee does not support displacement
yet and the discrepancy between the viewport and final render is problematic.
This means the shader can now be used for procedural texturing. New
settings on the node are Samples, Inside, Local Only and Distance.
Original patch by Lukas with further changes by Brecht.
Differential Revision: https://developer.blender.org/D3479
The automatic mode checks all Enviroment Texture nodes and picks the largest image's resolution.
If there are no Enviroment Textures, it just uses the old default.
Also, the sampling map now isn't limited to square shapes. The automatic detection uses the exact image size,
the manual UI option now halves the value to get the height.
A default aspect ratio of 2:1 makes sense since this is what most HDRIs use.
Reviewers: brecht, sergey
Differential Revision: https://developer.blender.org/D3477
