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.
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
The implementation is currently optimized to load animation sequences once
and then quickly scrubbing through them. Later on an option should be added
to optimize for memory usage and only load the current frame into memory.
Currently mesh and curve objects are supported, including support for UV and
vertex color attributes. Missing still is support for arbitrary attributes and
motion blur, as well as better handling of changing topology. Shader assignments
are made using FaceSets found in the Alembic archive.
The animation (and constant) data of the objects inside the Alembic archive is
loaded at once at the beginning of the render and kept inside a cache. At each
frame change we simply update the right socket of the corresponding Cycles node
if the data is animated. This allows for fast playback in the viewport
(depending on the scene size and compute power).
Note this is not yet exposed in the Blender UI, it's a feature that is still under
development and not ready for general use.
Ref T79174, D3089
Procedurals are nodes in the scene that can generate an arbitrary number of
other nodes at render time. This will be used to implement an Alembic procedural
that can load an Alembic file into Cycles nodes. In the future we also expect to
have a USD procedural.
Direct loading of such files at render time is a standard feature in other
production renderers. Reasons to support this are memory usage and performance,
delayed loading of heavy scene data until rendering, Cycles standalone rendering
using standard file formats beyond our XML files, and shared functionality for
Cycles integration in multiple 3D apps.
Ref T79174, D3089
Modifications to triangle shader association were not considered when checking for updates and the associated device data array was not tagged as modified so it was not resent to the device(s).
This optimizes device updates (during user edits or frame changes in
the viewport) by avoiding unnecessary computations. To achieve this,
we use a combination of the sockets' update flags as well as some new
flags passed to the various managers when tagging for an update to tell
exactly what the tagging is for (e.g. shader was modified, object was
removed, etc.).
Besides avoiding recomputations, we also avoid resending to the devices
unmodified data arrays, thus reducing bandwidth usage. For OptiX and
Embree, BVH packing was also multithreaded.
The performance improvements may vary depending on the used device (CPU
or GPU), and the content of the scene. Simple scenes (e.g. with no adaptive
subdivision or volumes) rendered using OptiX will benefit from this work
the most.
On average, for a variety of animated scenes, this gives a 3x speedup.
Reviewed By: #cycles, brecht
Maniphest Tasks: T79174
Differential Revision: https://developer.blender.org/D9555
Branched path tracing is not supported for OptiX, and it would still use the
number of AA samples from there when branched path was enabled by the user
earlier but auto disabled and hidden in the UI when using OptiX.
Ref D10159
Tile stealing may steal a CPU tile buffer and move it to the GPU, but next time around that
tile may be re-used on the CPU again (in progressive refinement mode). The buffer would
still be on the GPU then though, so is inaccessible to the CPU. As a result Blender crashed
when the CPU tried to write results to that tile buffer.
This fixes that by ensuring a stolen tile buffer is moved back to the device it is used on before
rendering.
The OptiX denoiser is part of the OptiX device, so to the tile manager looks like a GPU device. As a
result the tile stealing implementation erroneously stole CPU tiles and moved them to that OptiX
device, even though in this configuration the OptiX device was only set up for denoising and not
rendering. Launching the render kernel therefore caused a crash because of a missing AS etc.
This fixes that by ensuring tiles can only be stolen by devices that support render tiles.
Changing the geometry in the current scene caused the primitive offsets for all geometry to
change, but the values would not be updated in all bottom-level BVH structures. Rendering
artifacts and crashes where the result. This fixes that by ensuring all BVH structures are
updated when the primitive offsets change.
This is relatively expensive and as per the OSL spec, this value is not
expected to be meaningful for non-light shaders. This makes viewport updates
a little faster.
As a side effect also fixes T82723, viewport refresh issue with volume density.
The shaders were not tagged for a needed geometry update when the displacement method was modified, neither were the Geometry and Object managers.
Reviewed By: kevindietrich
Maniphest Tasks: T75539
Differential Revision: https://developer.blender.org/D8896
Don't refuse to load 5-channel images, instead drop any channels after the 4th
and hope that the first channels represent RGBA.
Differential Revision: https://developer.blender.org/D9820
Adds support for building multiple BVH types in order to support using both CPU and OptiX
devices for rendering simultaneously. Primitive packing for Embree and OptiX is now
standalone, so it only needs to be run once and can be shared between the two. Additionally,
BVH building was made a device call, so that each device backend can decide how to
perform the building. The multi-device for instance creates a special multi-BVH that holds
references to several sub-BVHs, one for each sub-device.
Reviewed By: brecht, kevindietrich
Differential Revision: https://developer.blender.org/D9718
The issue is caused by stale data on the Mesh Node which is not cleared
during synchronizing since the socket API refactor so that we can detect
changes. However, synchronization only updates the sockets of the Mesh,
so other properties were left with outdated values.
This caused an underflow when computing attribute size for undisplaced
coordinates as it was using the current number of vertices minus the
previous count of subdivision vertices, which at this point should be 0.
Added a simple method to clear non socket data. Also modified
Mesh.add_undisplaced to always use an ATTR_PRIM_GEOMETRY as the data is
not subdivided yet and it avoids any further issues regarding computing
attribute sizes.
This infinite loop is caused by a conflict between the volume mesh
creation which unintentionally clears the shaders before early exiting
when no grid is found, and the Blender exporter which adds back the
shaders causing us to reupdate as the shaders changed.
To fix this simply preserve the shaders on the Volume node.
