Previously, the lifetimes of anonymous attributes were determined by
reference counts which were non-deterministic when multiple threads
are used. Now the lifetimes of anonymous attributes are handled
more explicitly and deterministically. This is a prerequisite for any kind
of caching, because caching the output of nodes that do things
non-deterministically and have "invisible inputs" (reference counts)
doesn't really work.
For more details for how deterministic lifetimes are achieved, see D16858.
No functional changes are expected. Small performance changes are expected
as well (within few percent, anything larger regressions should be reported as
bugs).
Differential Revision: https://developer.blender.org/D16858
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
This patch refactors the instance-realization code and adds new functionality.
* Named and anonymous attributes are propagated from instances to the
realized geometry. If the same attribute exists on the geometry and on an
instance, the attribute on the geometry has precedence.
* The id attribute has special handling to avoid creating the same id on many
output points. This is necessary to make e.g. the Random Value node work
as expected afterwards.
Realizing instance attributes has an effect on existing files, especially due to the
id attribute. To avoid breaking existing files, the Realize Instances node now has
a legacy option that is enabled for all already existing Realize Instances nodes.
Removing this legacy behavior does affect some existing files (although not many).
We can decide whether it's worth to remove the old behavior as a separate step.
This refactor also improves performance when realizing instances. That is mainly
due to multi-threading. See D13446 to get the file used for benchmarking. The
curve code is not as optimized as it could be yet. That's mainly because the storage
for these attributes might change soonish and it wasn't worth optimizing for the
current storage format right now.
```
1,000,000 x mesh vertex: 530 ms -> 130 ms
1,000,000 x simple cube: 1290 ms -> 190 ms
1,000,000 x point: 1000 ms -> 150 ms
1,000,000 x curve spiral: 1740 ms -> 330 ms
1,000,000 x curve line: 1110 ms -> 210 ms
10,000 x subdivided cylinder: 170 ms -> 40 ms
10 x subdivided spiral: 180 ms -> 180 ms
```
Differential Revision: https://developer.blender.org/D13446
