The depsgraph CoW mechanism is a bit of a misnomer. It creates an
evaluated copy for data-blocks regardless of whether the copy will
actually be written to. The point is to have physical separation between
original and evaluated data. This is in contrast to the commonly used
performance improvement of keeping a user count and copying data
implicitly when it needs to be changed. In Blender code we call this
"implicit sharing" instead. Importantly, the dependency graph has no
idea about the _actual_ CoW behavior in Blender.
Renaming this functionality in the despgraph removes some of the
confusion that comes up when talking about this, and will hopefully
make the depsgraph less confusing to understand initially too. Wording
like "the evaluated copy" (as opposed to the original data-block) has
also become common anyway.
Pull Request: https://projects.blender.org/blender/blender/pulls/118338
Since the normals are stored in a shared cache, tagging them dirty
recreated the cache from scratch when it was shared. Instead,
add a function that updates the cache in the same call as tagging
it dirty. This keeps the old state of the cache around even if it was
shared, and reflects the way that it's really the PBVH and sculpt
mode managing the dirty status of normals while sculpt mode
is active.
One consequence is that the BVH cache and the triangulation
cache need to be tagged dirty manually. I'd like to avoid abstracting
this more than necessary, because I'm hoping in the long term
different caching abstractions like a more global cache that takes
implicit sharing versions into account will make this complexity
unnecessary.
Fixes#111628, #111563
Pull Request: https://projects.blender.org/blender/blender/pulls/111641
Listing the "Blender Foundation" as copyright holder implied the Blender
Foundation holds copyright to files which may include work from many
developers.
While keeping copyright on headers makes sense for isolated libraries,
Blender's own code may be refactored or moved between files in a way
that makes the per file copyright holders less meaningful.
Copyright references to the "Blender Foundation" have been replaced with
"Blender Authors", with the exception of `./extern/` since these this
contains libraries which are more isolated, any changed to license
headers there can be handled on a case-by-case basis.
Some directories in `./intern/` have also been excluded:
- `./intern/cycles/` it's own `AUTHORS` file is planned.
- `./intern/opensubdiv/`.
An "AUTHORS" file has been added, using the chromium projects authors
file as a template.
Design task: #110784
Ref !110783.
When the loose edge and vertex status are cached in the source mesh and
the combination of selection domain and mode don't add loose elements,
copy the cache status to avoid recomputation. In a test with a 1 million
face grid:
- All: 23 -> 30 FPS
- Only faces: 22 -> 23.5 FPS
- Only edges and faces: 24 -> 27 FPS
Also remove unnecessary includes and fix a build error introduced in
the last commit to this area from an inconsistent forward declaration.
A lot of files were missing copyright field in the header and
the Blender Foundation contributed to them in a sense of bug
fixing and general maintenance.
This change makes it explicit that those files are at least
partially copyrighted by the Blender Foundation.
Note that this does not make it so the Blender Foundation is
the only holder of the copyright in those files, and developers
who do not have a signed contract with the foundation still
hold the copyright as well.
Another aspect of this change is using SPDX format for the
header. We already used it for the license specification,
and now we state it for the copyright as well, following the
FAQ:
https://reuse.software/faq/
Bounding box calculation can be a large in some situations, especially
instancing. This patch caches the min and max of the bounding box in
runtime data of meshes, point clouds, and curves, implementing part of
T96968.
Bounds are now calculated lazily-- only after they are tagged dirty.
Also, cached bounds are also shared when copying geometry data-blocks
that have equivalent data. When bounds are calculated on an evaluated
data-block, they are also accessible on the original, and the next
evaluated ID will also share them. A geometry will stop sharing bounds
as soon as its positions (or radii) are changed.
Just caching the bounds gave a 2-3x speedup with thousands of mesh
geometry instances in the viewport. Sharing the bounds can eliminate
recalculations entirely in cases like copying meshes in geometry nodes
or the selection paint brush in curves sculpt mode, which causes a
reevaluation but doesn't change the positions.
**Implementation**
The sharing is achieved with a `shared_ptr` that points to a cache mutex
(from D16419) and the cached bounds data. When geometries are copied,
the bounds are shared by default, and only "un-shared" when the bounds
are tagged dirty.
Point clouds have a new runtime struct to store this data. Functions
for tagging the data dirty are improved for added for point clouds
and improved for curves. A missing tag has also been fixed for mesh
sculpt mode.
**Future**
There are further improvements which can be worked on next
- Apply changes to volume objects and other types where it makes sense
- Continue cleanup changes described in T96968
- Apply shared cache design to more expensive data like triangulation
or normals
Differential Revision: https://developer.blender.org/D16204
