Cycles has a sample offset feature allowing users to render X samples
in a single frame on one device, then the remaining Y samples later or
on a different device and combine them back together at the end.
However in most situations the result from using this method was
different, and usually lower quality than rendering all the samples in
one go.
This was because Cycles tunes it's random number sequence for the
number of samples being rendered. And the random number sequence was
being tuned for the wrong number of samples in the case that a user
was using the sample offset.
This commit fixes this issue by adding a "sample subset" feature.
The user specifies the total sample count being rendered across all
devices in the existing `Max Samples` parameter, then specifies per
device which subset of samples will be rendered (E.g. Render samples
0-1024 out of a 0-2048 range).
This commit also contains some additional clean up work
inside Cycles related to the area being changed.
Co-authored-by: Brecht Van Lommel <brecht@blender.org>
Pull Request: https://projects.blender.org/blender/blender/pulls/132961
Check was misc-const-correctness, combined with readability-isolate-declaration
as suggested by the docs.
Temporarily clang-format "QualifierAlignment: Left" was used to get consistency
with the prevailing order of keywords.
Pull Request: https://projects.blender.org/blender/blender/pulls/132361
* Use .empty() and .data()
* Use nullptr instead of 0
* No else after return
* Simple class member initialization
* Add override for virtual methods
* Include C++ instead of C headers
* Remove some unused includes
* Use default constructors
* Always use braces
* Consistent names in definition and declaration
* Change typedef to using
Pull Request: https://projects.blender.org/blender/blender/pulls/132361
Previously, Cycles would render up to 4SPP during viewport navigation when
using reduced resolution, even when the overall number of samples was set
lower.
This causes problems with the blue-noise pattern, so ensure that the
number of samples is always clamped to the configured maximum.
This is an oversight of #122543, for which benchmarking was done in
the headless mode.
The solution is to tweak policy a little bit, and keep refresh intervals
low for the first 10 seconds of render, after which increase updates to
every 15 seconds. Doing so allows:
- Have quick cancel of complex files when the error is noticed during
the first few samples.
- Have more predictable cancel time after long render.
- Mitigate the performance regression.
This does not fully solve the regression, but it makes it much more
manageable. There are some compromises to be done from the performance
for the UI renders. The interactivity is also not as fantastic, but it
could be solved later by introducing some "Instant Cancel" operations
which would be able to also stop render in the middle of a sample.
Performance measured with the Spring file (path tracing time in seconds):
Samples: 300 1024 2048
Base (prior to #122543): 29.1 85.4 174.1
This patch: 37.0 95.7 180.2
This is measured on M2 Ultra GPU render.
The penalty is close to a constant time (the time within which a more
interactive cancel is possible.
Pull Request: https://projects.blender.org/blender/blender/pulls/122658
In some of the complex scenes it could a very long time for Cycles
to respond to cancel request. This is because Cycles only cancels
render at a consistent state of render buffer: when all scheduled
samples are rendered.
This was caused by the render scheduler over-scheduling the number
of samples in an attempt to improve occupancy of the GPU.
This fix makes it so the scheduler only compensates for the low
occupancy if rendering can happen within a desired update time.
There is no visible difference in the benchmark scenes with this
change.
Pull Request: https://projects.blender.org/blender/blender/pulls/122543
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.
This changes the maximum viewport resolution divider for Cycles to
help users get a more responsive viewport.
This is done by changing the maximum viewport resolution divider
to a divider that aims to have the largest axis of the viewport
roughly equal to 128 pixels.
Depending on the circumstances, this change can result in a few
noticeable differences:
- Users with slow hardware and a large pixel_size, or slow hardware
and a low resolution screen, may observe a higher resolution viewport
during navigation, making the scene more readable. However this comes
at the cost of reduced responsiveness.
- Users with slow hardware and a low pixel_size and high
resolution screen may observe a lower resolution viewport during
navigation, providing a more responsive viewport during navigation.
Along with that, how Cycles iterates through resolution dividers
is changed to promote quick transitions between resolution dividers.
Meaning users don't need to wait through as many iterations to get
from a low navigation resolution to a 1:1 viewport resolution.
Pull Request: https://projects.blender.org/blender/blender/pulls/105581
As a side effect of this change, more resolution divisions are now available.
Before this patch the possible resolution divisions were all powers of two.
Now the possible resolution divisions are the multiples of pixel_size.
This increase in possible resolution divisions is the same idea proposed in https://archive.blender.org/developer/D13590.
In that patch there were concerns that this will increase the time between a user navigating
and seeing the 1:1 render. To my knowledge this is a non-issue and there should be
little to no increase in time between those two events.
Pull Request #104450
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
This patch adds a Hydra render delegate to Cycles, allowing Cycles to be used for rendering
in applications that provide a Hydra viewport. The implementation was written from scratch
against Cycles X, for integration into the Blender repository to make it possible to continue
developing it in step with the rest of Cycles. For this purpose it follows the style of the rest of
the Cycles code and can be built with a CMake option
(`WITH_CYCLES_HYDRA_RENDER_DELEGATE=1`) similar to the existing standalone version
of Cycles.
Since Hydra render delegates need to be built against the exact USD version and other
dependencies as the target application is using, this is intended to be built separate from
Blender (`WITH_BLENDER=0` CMake option) and with support for library versions different
from what Blender is using. As such the CMake build scripts for Windows had to be modified
slightly, so that the Cycles Hydra render delegate can e.g. be built with MSVC 2017 again
even though Blender requires MSVC 2019 now, and it's possible to specify custom paths to
the USD SDK etc. The codebase supports building against the latest USD release 22.03 and all
the way back to USD 20.08 (with some limitations).
Reviewed By: brecht, LazyDodo
Differential Revision: https://developer.blender.org/D14398
* 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
Sample offset was not accounted for in the adaptive sampling code and caused
issues, like immediately applied adaptive filtering, with non-zero values.
Differential Revision: https://developer.blender.org/D13510
Adds hysteresis to the resolution divider algorithm to avoid having the resolution bounce around when on the boundary of two resolutions.
Reviewed By: brecht, leesonw
Differential Revision: https://developer.blender.org/D12385
The calculation based on preserving device occupancy was conflicting
with the fact that time limit needs to render less samples at the last
round of render work.
For example, rendering BMW27 for 30sec on i9-11900k was actually
rendering for almost a minute. Now the render time limit is respected
much more close.
Differential Revision: https://developer.blender.org/D13269
This patch exposes the sampling offset option to Blender. It is located in the "Sampling > Advanced" panel.
For example, this can be useful to parallelize rendering and distribute different chunks of samples for each computer to render.
---
I also had to add this option to `RenderWork` and `RenderScheduler` classes so that the sample count in the status string can be calculated correctly.
Reviewed By: leesonw
Differential Revision: https://developer.blender.org/D13086
Remove prefix of filenames that is the same as the folder name. This used
to help when #includes were using individual files, but now they are always
relative to the cycles root directory and so the prefixes are redundant.
For patches and branches, git merge and rebase should be able to detect the
renames and move over code to the right file.
* Split render/ into scene/ and session/. The scene/ folder now contains the
scene and its nodes. The session/ folder contains the render session and
associated data structures like drivers and render buffers.
* Move top level kernel headers into new folders kernel/camera/, kernel/film/,
kernel/light/, kernel/sample/, kernel/util/
* Move integrator related kernel headers into kernel/integrator/
* Move OSL shaders from kernel/shaders/ to kernel/osl/shaders/
For patches and branches, git merge and rebase should be able to detect the
renames and move over code to the right file.
Only do denoising on the full-frame result. Saves render time.
Can re-consider in the future when/if we'll want to support
denoising during rendering (similar to viewport) to allow artists
to stop rendering when they see image to be good enough. Until
there is a design for that workflow stick to a more time efficient
rendering.
Differential Revision: https://developer.blender.org/D12662
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
