Overall, this commit reworks the component layering in the Principled BSDF
in order to ensure that energy is preserved and conserved.
This includes:
- Implementing support for the OSL `layer()` function
- Implementing albedo estimation for some of the closures for layering purposes
- The specular layer that the Principled BSDF uses has a proper tabulated
albedo lookup, the others are still approximations
- Removing the custom "Principled Diffuse" and replacing it with the classic
lambertian Diffuse, since the layering logic takes care of energy now
- Making the merallic component independent of the IOR
Note that this changes the look of the Principled BSDF noticeably in some
cases, but that's needed, since the cases where it looks different are the
ones that strongly violate energy conservation (mostly grazing reflections
with strong Specular).
Pull Request: https://projects.blender.org/blender/blender/pulls/110864
While the multiscattering GGX code is cool and solves the darkening problem at higher roughnesses, it's also currently buggy, hard to maintain and often impractical to use due to the higher noise and render time.
In practice, though, having the exact correct directional distribution is not that important as long as the overall albedo is correct and we a) don't get the darkening effect and b) do get the saturation effect at higher roughnesses.
This can simply be achieved by adding a second lobe (https://blog.selfshadow.com/publications/s2017-shading-course/imageworks/s2017_pbs_imageworks_slides_v2.pdf) or scaling the single-scattering GGX lobe (https://blog.selfshadow.com/publications/turquin/ms_comp_final.pdf). Both approaches require the same precomputation and produce outputs of comparable quality, so I went for the simple albedo scaling since it's easier to implement and more efficient.
Overall, the results are pretty good: All scenarios that I tested (Glossy BSDF, Glass BSDF, Principled BSDF with metallic or transmissive = 1) pass the white furnace test (a material with pure-white color in front of a pure-white background should be indistinguishable from the background if it preserves energy), and the overall albedo for non-white materials matches that produced by the real multi-scattering code (with the expected saturation increase as the roughness increases).
In order to produce the precomputed tables, the PR also includes a utility that computes them. This is not built by default, since there's no reason for a user to run it (it only makes sense for documentation/reproducibility purposes and when making changes to the microfacet models).
Pull Request: https://projects.blender.org/blender/blender/pulls/107958
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
For file formats like PNG, JPEG and TIFF. Eventually this should use
the OpenColorIO view transform, but this at least makes the image
closer to what it should be in most cases.
Differential Revision: https://developer.blender.org/D16482
This was previously needed due to poor compatibility between Visual Studio and
NVCC. But it has not been used for a while now as compatibility seems to have
improved.
This cleans up the OpenGL build flags and linking.
It additionally also removes some dead code.
One of these dead code paths is WITH_X11_ALPHA which actually never was
active even with the build flag on. The call to use this was never
called because the default initializer for GHOST was set to have it off
per default. Nothing called this function with a boolean value to enable it.
These cleanups are needed to support true headless OpenGL rendering.
Without these cleanups libepoxy will fail to load the correct OpenGL
Libraries as we have already linked them to the blender binary.
Reviewed By: Brecht, Campbell, Jeroen
Differential Revision: http://developer.blender.org/D15554
With libepoxy we can choose between EGL and GLX at runtime, as well as
dynamically open EGL and GLX libraries without linking to them.
This will make it possible to build with Wayland, EGL, GLVND support while
still running on systems that only have X11, GLX and libGL. It also paves
the way for headless rendering through EGL.
libepoxy is a new library dependency, and is included in the precompiled
libraries. GLEW is no longer a dependency, and WITH_SYSTEM_GLEW was removed.
Includes contributions by Brecht Van Lommel, Ray Molenkamp, Campbell Barton
and Sergey Sharybin.
Ref T76428
Differential Revision: https://developer.blender.org/D15291
Long term, this should replace the XML format. This reuses the Hydra render
delegate implementation, and so supports the same features. The same command
line options and GUI work for both XML and USD also.
The implementation of this is still disabled, waiting for some refactoring of
USD library linking. However we want the Cycles code to be in sync between
repositories for the 3.2 release.
Ref T96731
* Leave code for building the render delegate against other applications and
their USD libraries to the Cycles repository, since this is not a great fit.
In the Blender repository, always use Blender's USD libraries now that they
include Hydra support.
* Hide non-USD symbols from the hdCycles shared library, to avoid library
version conflicts.
* Share Apple framework linking between the standalone app and plugin.
* Add cycles_hydra module, to be shared between the standalone app and plugin.
* Bring external libs code in sync with standalone repo, adding various missing
libraries.
* Move some cmake include directories to the top level cycles source folder
because we need to control their global order, to ensure we link against the
correct headers with mixed Blender libraries and external USD libraries.
* Add missing GLEW and hgiGL libraries for Hydra
* Fix wrong case sensitive include
* Fix link errors by adding external libs to static Hydra lib
* Work around weird Hydra link error with MAX_SAMPLES
* Use Embree by default for Hydra
* Sync external libs code with standalone
* Update version number to match Blender
* Remove unneeded CLEW/GLEW from test executable
None of this should affect Cycles in Blender.
Ref T96731
GLUT does not support offscreen contexts, which is required for the new
display driver. So we use SDL instead. Note that this requires using a
system SDL package, the Blender precompiled SDL does not include the video
subsystem.
There is currently no text display support, instead info is printed to
the terminal. This would require adding an embedded font and GLSL shaders,
or using GUI library.
Another improvement to be made is supporting OpenColorIO display transforms,
right now we assume Rec.709 scene linear and display.
All OpenGL, GLEW and SDL code was move out of core cycles and into
app/opengl. This serves as a template for apps that want to integrate
Cycles interactive rendering, with a simple OpenGLDisplayDriver example.
In general this would be adapted to the graphics API and color management
used by the app.
Ref T91846
* 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
Use a shorter/simpler license convention, stops the header taking so
much space.
Follow the SPDX license specification: https://spdx.org/licenses
- C/C++/objc/objc++
- Python
- Shell Scripts
- CMake, GNUmakefile
While most of the source tree has been included
- `./extern/` was left out.
- `./intern/cycles` & `./intern/atomic` are also excluded because they
use different header conventions.
doc/license/SPDX-license-identifiers.txt has been added to list SPDX all
used identifiers.
See P2788 for the script that automated these edits.
Reviewed By: brecht, mont29, sergey
Ref D14069
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.
* Add OutputDriver, replacing function callbacks in Session.
* Add PathTraceTile, replacing tile access methods in Session.
* Add more detailed comments about how this driver should be implemented.
* Add OIIOOutputDriver for Cycles standalone to output an image.
Differential Revision: https://developer.blender.org/D12627
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
The changes to the socket API were not applied to the standalone app.
Also modify Camera.compute_auto_viewplane() to use Camera.full_width and Camera.full_height as it is not possible to publicly access Camera.width and Camera.height anymore, so the aspect ratio could be computed with stale data.
Differential Revision: https://developer.blender.org/D9961
* Support precompiled libraries on Linux
* Add license headers
* Refactoring to deduplicate code
Includes work by Ray Molenkamp and Grische for precompiled libraries.
Ref D8769
I'm not sure if the Sky was deliberately left out or was just waiting for a
better moment, but so many I was disappointed that Sky in EEVEE is
completely white.
There are already 2 implementations (osl and gpu) so this is the third one.
Looking at other cases it seems that we are not supposed to share sources
between cycles and the rest? So the new util_sky_model files are just
copies of what is already in cycles, except that the data file uses the RGB
variant of the Hosek/Wilkie model, because we output RGB anyway (but can be
easily changed to XYZ if desired - the results are nearly identical).
I am not sure if it is okay to pass 3*9 float values as 3 mat4 uniforms (I
wanted to use mat3 but it does not work).
Also, should I cache the sky model data between renders if the parameters
do not change?
Reviewed By: fclem, brecht
Differential Revision: https://developer.blender.org/D7108
Campbell Barton
Lukas Stockner
Brecht Van Lommel
Sergey Sharybin
howetuft
Sebastian Parborg
Christian Rauch
Charles Flèche
Brecht Van Lommel
Campbell Barton
Stefan Werner
Szymon Ulatowski
Ray Molenkamp
Dalai Felinto