Currently, during baking each pixel stores a seed input that comes from the
Blender side. This is only needed for vertex color baking, however -
for regular image baking, we can just as well hash the pixel coordinates.
Therefore, we can save some memory (4 byte per pixel) by splitting the seed
info out into a separate pass and only storing it when needed.
Pull Request: https://projects.blender.org/blender/blender/pulls/122806
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
Previously, GPU denoisers were ignoring settings about render
configuration and were using any available GPU. With these changes,
GPU denoisers will use the device selected in Blender Cycles
settings.
This allows any GPU denoiser to be used with CPU rendering.
Pull Request: https://projects.blender.org/blender/blender/pulls/118841
The problem here was that `free_data_after_sync` frees the particle cache in headless or locked-UI mode, but the second view doesn't regenerate them.
For multi-view renders, dropping caches is a tradeoff between compute and memory - dropping allows to reduce peak memory usage, but requires recomputation for the next view. With the current design however, dropping is not something that is easily achievable anyways (see the referenced bugs). So until something more reliable and better fitting is implemented, keep the data from Blender side until the last view.
Since `free_data_after_sync` doesn't do anything for baking or viewport renders anyways, it's easiest to just move this out into `BlenderSession::render` since that already checks whether another view is still outstanding.
Also fixes#73221 and #107589.
Pull Request: https://projects.blender.org/blender/blender/pulls/120543
The issue was caused by the special code in Cycles which clears object
caches when it thinks they are not needed. We should not free caches of
grease pencils because it is needed later by a separate render engine.
Pull Request: https://projects.blender.org/blender/blender/pulls/120315
This feature is useful for many production scenarios as it allows for the
creation of separate render passes with specific worlds. This would help
workflows that require different skies or other backgrounds for compositing.
Ref #117919
Pull Request: https://projects.blender.org/blender/blender/pulls/117920
OpenImageDenoise API exposes two modes, high quality and balanced.
This currently only has effect on Nvidia devices, on which it
provides a noticeable performance improvement without visible
difference in quality. This change sets quality to balanced for
the viewport, and high quality for final frame rendering, as
it's what makes the most sense.
Ref #115045
Co-authored-by: Werner, Stefan <stefan.werner@intel.com>
Pull Request: #115265
Along with the 4.1 libraries upgrade, we are bumping the clang-format
version from 8-12 to 17. This affects quite a few files.
If not already the case, you may consider pointing your IDE to the
clang-format binary bundled with the Blender precompiled libraries.
The sampling pattern is only a debug setting at this point
and should not be used without the debug UI enabled where
users can actually see and edit the value.
Pull Request: https://projects.blender.org/blender/blender/pulls/112606
There are a couple of functions that create rna pointers. For example
`RNA_main_pointer_create` and `RNA_pointer_create`. Currently, those
take an output parameter `r_ptr` as last argument. This patch changes
it so that the functions actually return a` PointerRNA` instead of using
the output parameters.
This has a few benefits:
* Output parameters should only be used when there is an actual benefit.
Otherwise, one should default to returning the value.
* It's simpler to use the API in the large majority of cases (note that this
patch reduces the number of lines of code).
* It allows the `PointerRNA` to be const on the call-site, if that is desired.
No performance regression has been measured in production files.
If one of these functions happened to be called in a hot loop where
there is a regression, the solution should be to use an inline function
there which allows the compiler to optimize it even better.
Pull Request: https://projects.blender.org/blender/blender/pulls/111976
When WITH_CYCLES_DEBUG is set to ON the following errors are
printed to the console:
E0412 15:51:22.588564 7996345 sync.cpp:737] Unknown pass Guiding Color
E0412 15:51:22.588605 7996345 sync.cpp:737] Unknown pass Guiding Probability
E0412 15:51:22.588613 7996345 sync.cpp:737] Unknown pass Guiding Average Roughness
This change fixes this by treating the guiding passes the same
way as all other passes, solving the errors and making it possible
to visualize guiding passes in the viewport later on.
Pull Request: https://projects.blender.org/blender/blender/pulls/106863
For example
```
OIIOOutputDriver::~OIIOOutputDriver()
{
}
```
becomes
```
OIIOOutputDriver::~OIIOOutputDriver() {}
```
Saves quite some vertical space, which is especially handy for
constructors.
Pull Request: https://projects.blender.org/blender/blender/pulls/105594
The light tree itself is disabled on the AMD GPUs due to a compiler issue.
There are couple of places where this was not fully checked:
- The `light_sample` function in the kernel.
- The light threshold during synchronization
The former one is solved as easy as just adding an ifdef block.
The latter one is solved by delaying the threshold assignment for
later on.
Pull Request #105022
This patch adds a new "Kernel Optimization Level" dropdown menu to control Metal kernel specialisation. Currently this defaults to "full" optimisation, on the assumption that the changes proposed in D16371 will address usability concerns around app responsiveness and shader cache housekeeping.
Reviewed By: brecht
Differential Revision: https://developer.blender.org/D16514
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
Bugs that caused wrong renders should be fixed now, and tests that showed minor
floating point differences on platforms were tweaked to sidestep the problem.
Ref T77889
Uses a light tree to more effectively sample scenes with many lights. This can
significantly reduce noise, at the cost of a somewhat longer render time per
sample.
Light tree sampling is enabled by default. It can be disabled in the Sampling >
Lights panel. Scenes using light clamping or ray visibility tricks may render
different as these are biased techniques that depend on the sampling strategy.
The implementation is currently disabled on AMD HIP. This is planned to be fixed
before the release.
Implementation by Jeffrey Liu, Weizhen Huang, Alaska and Brecht Van Lommel.
Ref T77889
This was not working well in non-trivial scenes before the light tree, and now
it is even harder to make it work well with the light tree. It would average the
with equal weight for every light object regardless of intensity or distance, and
be quite noisy due to not working with multiple importance sampling.
We may restore this if were enough good use cases for the previous implementation,
but let's wait and see what the feedback is.
Some uses cases for this have been replaced by the shadow catcher passes, which
did not exist when this was added.
Ref T77889
It is not really used from any of the sources, including the
standalone app. Since we are moving to a more backend-independent
drawing it makes sense to remove header which was specific to
how Blender integrates Cycles into viewport.
There is probably some cleanup in CMake files is possible, but
there is some inter-dependency with USD.
Differential Revision: https://developer.blender.org/D16681
In T93382, the problem was that the Blender-side rendering code was
still generating the subsurface passes because the old render pass
flags were set, even though Cycles doesn't generate them anymore.
After a closer look, it turns out that the entire hardcoded pass
creation code can be removed. We already have an Engine API function
to query the list of render passes from the engine, so we might as
well just call that and create the returned passes.
Turns out that Eevee already did this anyways. On the Cycles side, it
allows to deduplicate a lot of `BlenderSync::sync_render_passes`.
Before, passes were defined in engine.py and in sync.cpp. Now, all
passes that engine.py returns are created automatically, so sync.cpp
only needs to handle a few special cases.
I'm not really concerned about affecting external renderer addons,
since they already needed to handle the old "builtin passes" in
their Engine API implementation anyways to make them show up in the
compositor. So, unless they missed that for like 10 releases, they
should not notice any difference.
Differential Revision: https://developer.blender.org/D16295
The attribute node already allows accessing attributes associated
with objects and meshes, which allows changing the behavior of the
same material between different objects or instances. The same idea
can be extended to an even more global level of layers and scenes.
Currently view layers provide an option to replace all materials
with a different one. However, since the same material will be applied
to all objects in the layer, varying the behavior between layers while
preserving distinct materials requires duplicating objects.
Providing access to properties of layers and scenes via the attribute
node enables making materials with built-in switches or settings that
can be controlled globally at the view layer level. This is probably
most useful for complex NPR shading and compositing. Like with objects,
the node can also access built-in scene properties, like render resolution
or FOV of the active camera. Lookup is also attempted in World, similar
to how the Object mode checks the Mesh datablock.
In Cycles this mode is implemented by replacing the attribute node with
the attribute value during sync, allowing constant folding to take the
values into account. This means however that materials that use this
feature have to be re-synced upon any changes to scene, world or camera.
The Eevee version uses a new uniform buffer containing a sorted array
mapping name hashes to values, with binary search lookup. The array
is limited to 512 entries, which is effectively limitless even
considering it is shared by all materials in the scene; it is also
just 16KB of memory so no point trying to optimize further.
The buffer has to be rebuilt when new attributes are detected in a
material, so the draw engine keeps a table of recently seen attribute
names to minimize the chance of extra rebuilds mid-draw.
Differential Revision: https://developer.blender.org/D15941
This adds path guiding features into Cycles by integrating Intel's Open Path
Guiding Library. It can be enabled in the Sampling > Path Guiding panel in the
render properties.
This feature helps reduce noise in scenes where finding a path to light is
difficult for regular path tracing.
The current implementation supports guiding directional sampling decisions on
surfaces, when the material contains a least one diffuse component, and in
volumes with isotropic and anisotropic Henyey-Greenstein phase functions.
On surfaces, the guided sampling decision is proportional to the product of
the incident radiance and the normal-oriented cosine lobe and in volumes it
is proportional to the product of the incident radiance and the phase function.
The incident radiance field of a scene is learned and updated during rendering
after each per-frame rendering iteration/progression.
At the moment, path guiding is only supported by the CPU backend. Support for
GPU backends will be added in future versions of OpenPGL.
Ref T92571
Differential Revision: https://developer.blender.org/D15286
The multi-dimensional Sobol pattern required us to carefully use as low
dimensions as possible, as quality goes down in higher dimensions. Now that we
have two sampling patterns that are at least as good, there is no need to keep
it around and the implementation can be simplified.
Differential Revision: https://developer.blender.org/D15788
Use lowercase rgba channel names which still by-passes lossy nature
of DWA compression and which also keeps external compositing tools
happy.
Thanks Steffen Dünner for testing this patch!
Differential Revision: https://developer.blender.org/D15834
The DWA compression code in OpenEXR has hardcoded rules which decides
which channels are lossy or lossless. There is no control over these
rules via API.
This change makes it so channel names of xyzw is used for cryptomatte
passes in Cycles. This works around the hardcoded rules in the DWA code
making it so lossless compression is used. It is important to use lower
case y channel name as the upper case Y uses lossy compression.
The change in the channel naming also makes it so the write code uses
32bit for the cryptomatte even when saving half-float EXR.
Fixes T96933: Cryptomatte layers saved incorrectly with EXR DWA compression
Fixes T88049: Cryptomatte EXR Output Bit Depth should always be 32bit
Differential Revision: https://developer.blender.org/D15823
This adds support for rendering motion blur for volumes, using their
velocity field. This works for fluid simulations and imported VDB
volumes. For the latter, the name of the velocity field can be set per
volume object, with automatic detection of velocity fields that are
split into 3 scalar grids.
A new parameter is also added to scale velocity for more artistic control.
Like for Alembic and USD caches, a parameter to set the unit of time in
which the velocity vectors are expressed is also added. For Blender gas
simulations, the velocity unit should always be in seconds, so this is
only exposed for volume objects which may come from external OpenVDB
files.
These parameters are available under the `Render` panels for the fluid
domain and the volume object data properties respectively.
Credits: kernel advection code from Tangent Animation's Blackbird based
on earlier work by Geraldine Chua
Differential Revision: https://developer.blender.org/D14629
Light groups are a type of pass that only contains lighting from a subset of light sources.
They are created in the View layer, and light sources (lamps, objects with emissive materials
and/or the environment) can be assigned to a group.
Currently, each light group ends up generating its own version of the Combined pass.
In the future, additional types of passes (e.g. shadowcatcher) might be getting their own
per-lightgroup versions.
The lightgroup creation and assignment is not Cycles-specific, so Eevee or external render
engines could make use of it in the future.
Note that Lightgroups are identified by their name - therefore, the name of the Lightgroup
in the View Layer and the name that's set in an object's settings must match for it to be
included.
Currently, changing a Lightgroup's name does not update objects - this is planned for the
future, along with other features such as denoising for light groups and viewing them in
preview renders.
Original patch by Alex Fuller (@mistaed), with some polishing by Lukas Stockner (@lukasstockner97).
Differential Revision: https://developer.blender.org/D12871
While the correlation may not work well with adaptive sampling, in practice
this appears to work ok in most cases
Automatic scrambling distance uses the minimum samples from adaptive sampling,
which provides a good default estimate to avoid artifacts.
Contributed by Alaska.
Differential Revision: https://developer.blender.org/D13325
