For Cycles, when enabling the Persistent Data option, the full render data
will be preserved from frame-to-frame in animation renders and between
re-renders of the scene. This means that any modifier evaluation, BVH
building, OpenGL vertex buffer uploads, etc, can be done only once for
unchanged objects. This comes at an increased memory cost.
Previously there option was named Persistent Images and had a more limited
impact on render time and memory.
When using multiple view layers, only data from a single view layer is
preserved to keep memory usage somewhat under control. However objects
shared between view layers are preserved, and so this can speedup such
renders as well, even single frame renders.
For Eevee and Workbench this option is not available, however these engines
will now always reuse the depsgraph for animation and multiple view layers.
This can significantly speed up rendering.
These engines do not support sharing the depsgraph between re-renders, due
to technical issues regarding OpenGL contexts. Support for this could be added
if those are solved, see the code comments for details.
This simulates the effect of a honeycomb or grid placed in front of a softbox.
In practice, it works by attenuating rays coming off-angle as a function of the
provided spread angle parameter.
Setting the parameter to 180 degrees poses no restrictions to the rays, making
the light behave the same way as before this patch.
The total light power is normalized based on the spread angle, so that the
light strength remains the same.
Differential Revision: https://developer.blender.org/D10594
The index_data_map was not cleared when clearing a cache, so this would just append
the new correct data to the end of the array instead of overwriting it, which would
cause us to then use outdated indices.
When the strength is initially set to zero, the shader graph is
optimized out to remove any node which will not be executed because of
this, which removes pretty much every single node, except for the
output. As the graph is empty, the world shader is made invisible to
rays so it is not evaluated in the kernel.
However, when the strength is then modified, the Background is not
updated as the modification happens on the Shader Node and not on the
Background Node, so it is never tagged as modified.
To fix this, we need to tag the Background as modified when its shader
is also modified so the Kernel data is properly updated.
Regression caused by rBbbe6d44928235cd4a5cfbeaf1a1de78ed861bb92.
As a rather premature optimization from rBbbe6d4492823, Object bounds
were only computed when either the Object or its Geometry were modified.
Prior to rB42198e9eb03b, this would work, as the Geometry was tagged as
modified if the Object's transform was also modified.
Since this tagging is not done anymore due to side effects, and since at
the time bounds are computed Objects were already processed and tag as
unmodified, the check on the modified status was always false.
For now remove this check, so the bounds are always unconditionally
updated. If this ever becomes a performance problem in large scenes with
motion blur, we will then try to find a way to nicely optimize it.
This would only affect BHV2 as OptiX and Embree handle object bounds
themselves.
Currently the procedural will add an entry to the cache for every frame
even if the data only changes seldomly. This means that in some cases we
will have duplicate data accross frames.
The cached data is now stored separately from the time information, and
an index is used to retrieve it based on time. This decoupling allows
for multiple frames to point to the same data.
To check if two arrays are the same, we compute their keys using the
Alembic library's routines (which is based on murmur3), and tell the
cache to reuse the last data if the keys match.
This can drastically reduce memory usage at the cost of more processing
time, although processing time is only increased if the topology may
change.
In order to update the BVH when only the transformations are changing,
we would tag the Object's Geometry as modified. However, when
displacement is used, and the vertices were not themselves modified,
this would cause us to redo the displacement on already displaced
vertices.
To fix this, use a specific update flag for detecting and notifying that
transformations were modified.
Regression caused by rBbbe6d44928235cd4a5cfbeaf1a1de78ed861bb92.
The crash is caused by an out of bound access in the kernel due to
missing data update when a Volume's voxel data changes. Although the
previous bounding mesh is cleared, the Volume Node was not tagged as
modified, and therefore never rebuilt.
To fix this, tag the Geometries (not just Volumes, to be more robust) as
modified in Geometry.clear().
Regression caused by rBbbe6d44928235cd4a5cfbeaf1a1de78ed861bb92.
Cycles, Eevee, OSL, Geo, Attribute
Based on outdated refract patch D6619 by @cubic_sloth
`refract` and `faceforward` are standard functions in GLSL, OSL and Godot shader languages.
Adding these functions provides Blender shader artists access to these standard functions.
Reviewed By: brecht
Differential Revision: https://developer.blender.org/D10622
Static initialization order was not guaranteed to be correct for node base
types. Now wrap all initialization in accessor functions to ensure the order
is correct.
Did not cause any known bug on Linux/macOS/Windows, but showed up on this
platform.
This type, CacheLookupResult, holds the data for the current time, or an
explanation as to why no data is available (already loaded, or simply
nothing available). This is useful to document the behavior of the code
but also, in future changes, to respond appropriately for missing data.
Inside of the procedural, instances are AlembicObjects which point to
the AlembicObject that they instance.
In Alembic, an instance is an untyped Object pointing to the original
(instanced) one through its source path. During the archive traversal we
detect such instances and, only if the instanced object is asked to be
rendered, set the instance's AlembicObject to point to the original's
AlembicObject.
Cycles Object Nodes are created for each AlembicObject, but only for
non-instances are Geometries created, which are then shared between
Object Nodes. It is supposed, and expected, that all instances share the
same shaders, which will be set to be the ones found on the original
object.
As for caching, the data cache for an AlembicObject is only valid for
non-instances and should not be read to or from as it is implicitly
shared.
This will help support instancing as cache building is now decoupled
from the logic to update the Nodes' sockets as data (and cache) will
need to be shared by different Geometries somehow, and also simplify
implementing different data caching methods by centralizing this
operation.
We need to explicitely tag the Attribute and AttributeSet as modified if
we change or add/remove data. This is more of a bandaid until attributes
handling is refactored to be able to reuse routines from the Attribute
API.
The Blender/Cycles XYZ color space has a D65 white point instead of E, and
this was not correctly accounted for both in the OpenColor config reading code
and the bundled config.
This meant that since the OpenColorIO v2 upgrade, the Linear ACES color space
was not working correctly, and other OpenColorIO configs defining
aces_interchange were not interpreted correctly.
The missing update has two sources:
The TimeSampling used for looking up transformations in the cache was
uninitialized. To fix this, simply use the TimeSampling from the last
transformation in the hierarchy (that is the object's parent), which
should also contain the time information for all of its parents.
The objects are not tagged for update when their trasformations change.
This issue seems to be caused by the reallocation flag not being set on
the device shader data array so it was never updated on the GPU although
the host memory was modified.
When primitive offsets change we need to rebuild or refit BVHs, however this
was also tagging other data as modified too late in the geometry update process.
Now ensure only the BVHs are updated.
Ref D10441
This patch has originally been written by Kévin Dietrich, thanks!
It is part of D10210.
As Brecht noted in D10210, this might not handle all cases yet.
I better solution should come soonish.
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
This crash is caused by accessing object data in the kernel at an out of bound index from a deleted instance.
Cycles represents instances as Object nodes sharing the same Geometry node, so we need to tag the GeometryManager for an update if some objects are added or removed as no geometry might have been added or removed in order to properly update the BVH and its associated data arrays.
Regression caused by rBbbe6d4492823.
