* Rename ambiguous rgb to scene_linear in some places
* Precompute matrices to directly go to scene instead of through XYZ
* Make function signatures more consistent
* Don't assume the display colorspace name fully defines the transform
to display space, this is not true in OpenColorIO 2 where view transforms
may be defined in more complexs ways than just specifying a colorspace.
* In places where we need to store the display colorspace name, resolve
<USE_DISPLAY_NAME> token manually.
Ref T96590
This enables the configuration to specify aliases for compatibility with other
configurations.
When a colorspace name is saved in a.blend, that is the alias of a colorspace
in the current configuration, it will show the main colorspace from the
configuration in the user interface and Python API instead.
Loading & saving the .blend file does not make any changes to the stored name,
so as to not make hidden modifications. Only when setting the property again
will the alias name be overwritten by the main colorspace name.
Fixes T96049
Differential Revision: https://developer.blender.org/D14419
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
Ref T84819
Build System
============
This is an API breaking new version, and the updated code only builds with
OpenColorIO 2.0 and later. Adding backwards compatibility was too complicated.
* Tinyxml was replaced with Expat, adding a new dependency.
* Yaml-cpp is now built as a dependency on Unix, as was already done on Windows.
* Removed currently unused LCMS code.
* Pystring remains built as part of OCIO itself, since it has no good build system.
* Linux and macOS check for the OpenColorIO verison, and disable it if too old.
Ref D10270
Processors and Transforms
=========================
CPU processors now need to be created to do CPU processing. These are cached
internally, but the cache lookup is not fast enough to execute per pixel or
texture sample, so for performance these are now also exposed in the C API.
The C API for transforms will no longer be needed afer all changes, so remove
it to simplify the API and fallback implementation.
Ref D10271
Display Transforms
==================
Needs a bit more manual work constructing the transform. LegacyViewingPipeline
could also have been used, but isn't really any simpler and since it's legacy
we better not rely on it.
We moved more logic into the opencolorio module, to simplify the API. There is
no need to wrap a dozen functions just to be able to do this in C rather than C++.
It's also tightly coupled to the GPU shader logic, and so should be in the same
module.
Ref D10271
GPU Display Shader
==================
To avoid baking exposure and gamma into the GLSL shader and requiring slow
recompiles when tweaking, we manually apply them in the shader. This leads
to some logic duplicaton between the CPU and GPU display processor, but it
seems unavoidable.
Caching was also changed. Previously this was done both on the imbuf and
opencolorio module levels. Now it's all done in the opencolorio module by
simply matching color space names. We no longer use cacheIDs from OpenColorIO
since computing them is expensive, and they are unlikely to match now that
more is baked into the shader code.
Shaders can now use multiple 2D textures, 3D textures and uniforms, rather
than a single 3D texture. So allocating and binding those adds some code.
Color space conversions for blending with overlays is now hardcoded in the
shader. This was using harcoded numbers anyway, if this every becomes a
general OpenColorIO transform it can be changed, but for now there is no
point to add code complexity.
Ref D10273
CIE XYZ
=======
We need standard CIE XYZ values for rendering effects like blackbody emission.
The relation to the scene linear role is based on OpenColorIO configuration.
In OpenColorIO 2.0 configs roles can no longer have the same name as color
spaces, which means our XYZ role and colorspace in the configuration give an
error.
Instead use the new standard aces_interchange role, which relates scene linear
to a known scene referred color space. Compatibility with the old XYZ role is
preserved, if the configuration file has no conflicting names.
Also includes a non-functional change to the configuraton file to use an
XYZ-to-ACES matrix instead of REC709-to-ACES, makes debugging a little easier
since the matrix is the same one we have in the code now and that is also
found easily in the ACES specs.
Ref D10274
BF-admins agree to remove header information that isn't useful,
to reduce noise.
- BEGIN/END license blocks
Developers should add non license comments as separate comment blocks.
No need for separator text.
- Contributors
This is often invalid, outdated or misleading
especially when splitting files.
It's more useful to git-blame to find out who has developed the code.
See P901 for script to perform these edits.
Summary:
Uses some magic pseudo-random which is actually a
texture coordinate hashing function.
TODOs:
- Dither noise is the same for all the frames.
- It's different from Floyd's dither we've been
using before.
- Currently CPU and GPU dithering used different
implementation. Ideally we need to use the same
dither in CPU.
Reviewers: brecht
Reviewed By: brecht
Differential Revision: http://developer.blender.org/D58
Summary:
Version of those libraries might be useful to know.
- OIIO and OCIO is exposed via bpy.app.oiio and bpy.app.ocio.
There're "supported", "version" and "version_string" defined
in those modules.
- OSL is available as _cycles.osl_version and _cycles.osl_version_string.
Reviewers: campbellbarton
Reviewed By: campbellbarton
CC: dingto
Differential Revision: http://developer.blender.org/D79
The title says it all, now having curve mapping
enabled in color management settings wouldn't
force fallback from GLSL to CPU based color space
conversion.
This commit implement's OCIO's Looks idea which
is about applying some color correction on the
buffer before it get's affected by a display
transform.
This is mainly used to modify images in an
artistics way.
Currently we've got looks generated from film
response curves for all sorts of cameras.
Patch by both of me and Brecht.
shader for converting colors from linear to display space, based on the scene
color management settings.
if engine.support_display_space_shader(scene): # test graphics card support
engine.bind_display_space_shader(scene)
# draw pixels ..
engine.unbind_display_space_shader()
- GLSL shader wasn't aware of alpha predivide option,
always assuming alpha is straight. Gave wrong results
when displaying transparent float buffers.
- GLSL display wasn't aware of float buffers with number
of channels different from 4, crashing when trying to
display image with different number of channels.
This required a bit larger changes, namely now it's
possible to pass format (GL_RGB, GL_RGBAm GL_LUMINANCE)
to glaDrawPixelsTex, This also implied adding format to
glaDrawPixelsAuto and modifying all places where this
functions are called.
Now GLSL will handle both 3 and 4 channels buffers,
single channel images are handled by CPU.
- Replaced hack for render result displaying with a bit
different hack.
Namely CPU conversion will happen only during render,
once render is done GLSL would be used for displaying
render result on a screen.
This is so because of the way renderer updates parts
of the image -- it happens without respect to active
render layer in image user. This is harmless because
only display buffer is modifying, but this is tricky
because we don't have original buffer opened during
rendering.
One more related fix here was about when rendering
multiple layers, wrong image would be displaying when
rendering is done. Added a signal to invalidate
display buffer once rendering is done (only happens
when using multiple layers). This solves issue with
wrong buffer stuck on the display when using regular
CPU display space transform and if GLSL is available
it'll make image displayed with a GLSL shader.
- As an additional change, byte buffers now also uses
GLSL display transform.
So now only dutehr and RGB curves are stoppers for
using GLSL for all kind of display transforms.
Implemented using GLSL API from OpenColorIO library and
some general functions were added to it's c-api:
- OCIO_setupGLSLDraw prepares OpenGL context for GPU-based
transformation for a giver processor.
This function compiles and links shader, sets up it's
argument. After this transformation would be applied
on an image displaying as a 2D texture.
So, glaDrawPixelsTex called after OCIO_setupGLSLDraw will
do a proper color space transform.
- OCIO_finishGLSLDraw restores OpenGL context after all
color-managed display is over.
- OCIO_freeOGLState frees allocated state structure used
for cacheing some GLSL-related stuff.
There're some utility functions in IMB_colormanagent which
are basically proxies to lower level OCIO functions but
which could be used from any place in blender.
Chacheing of movie clip frame on GPU is also removed now,
and either glaDrawPixelsTex or glaDrawPixelsAuto are used
for display now. This is so no code duplication happens
now and no large textures are lurking around in GPU memory.
Known issues:
- Texture buffer and GLSL are no longer checking for
video card capabilities, possibly could lead to some
artifacts on crappy drivers/cards.
- Only float buffers are displaying using GLSL, byte
buffers will still use fallback display method.
This is to be addressed later.
- If RGB curves are used as a part of display transform,
GLSL display will also be disabled. This is also thing
to be solved later.
Additional changes:
- glaDrawPixelsTexScaled will now use RGBA16F as an
internal format of storing textures when it's used
to draw float buffer. This is needed so LUT are
applied without precision loss.
ocio configuration file failed to load
This solves issues with infinite NULL-checks to prevent crashes in
such situations. Currently only happens if there's no configuration
file at all, but could be tweaked further to fallback if this file
isn't usable by blender.
