This fixes the glitching hairs described in T56408, T63534, and possibly
also T63534.
The fix consists of returning the original mesh (i.e. as visible in edit
mode) when constructing the ORCO mesh. This allows a static set of
coordinates to be used when computing the child hair positions.
The original mesh is only returned when it has the same topology (at
least same number of vertices, loops, and polys. It's up the author of
the Alembic file to ensure stable geometry when it's desired to be
compatible with Blender's hair system.
Reviewers: mont29, brecht
Differential Revision: https://developer.blender.org/D5492
The `AbcMetaballWriter` now subclasses `AbcGenericMeshWriter` instead of
wrapping an `AbcMeshWriter`. `AbcGenericMeshWriter` was created for this
purpose (writing non-mesh objects as mesh to Alembic) and performs the work
in a cleaner and, more importantly, not crashing way.
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This is often invalid, outdated or misleading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.
C++11 doesn't need the space between '> >' in a nested templated
declaration, so instead of `std::vector<std::pair<a, b> >` we can now
write `std::vector<std::pair<a, b> >`.
It's now possible to export curves and NURBS as mesh data to Alembic.
This allows artists to do any crazy thing on curves and export the
visual result to Alembic for interoperability with other software (or
caching for later use, etc.). It's an often-requested feature.
This works around T60503 and the fixes export part of T51311.
Note that exporting zero-width curves is currently not supported, as
exporting a faceless mesh (e.g. just edges and vertices) is not
supported by the mesh writer at all.
To test, create a curve with thickness (for example extruded), export to
Alembic and check the 'Curves to Mesh' checkbox in the export options.
Reviewers: sergey
Differential Revision: https://developer.blender.org/D4213
I moved most of the `AbcMeshWriter` code to a new class
`AbcGenericMeshWriter`. The latter is an abstract class and does not
make any assumptions about the type of Blender object being written.
This makes it possible to write metaballs, curves, nurbs surfaces, etc.
as mesh to Alembic files.
The `AbcMeshWriter` class now is the concrete implementation of
`AbcGenericMeshWriter` for writing mesh objects.
Reviewers: sergey
Differential Revision: https://developer.blender.org/D4213
The depsgraph was always created within a fixed evaluation context. Passing
both risks the depsgraph and evaluation context not matching, and it
complicates the Python API where we'd have to expose both which is not so
easy to understand.
This also removes the global evaluation context in main, which assumed there
to be a single active scene and view layer.
Differential Revision: https://developer.blender.org/D3152
- Only basis balls are exported, as they represent the resulting mesh.
As a result the mesh is written to Alembic using the name of the basis
ball.
- MetaBalls are converted to a mesh on every frame, then an
AbcMeshWriter is used to write that mesh to Alembic.
When a mesh changes its number of vertices during the animation,
Blender rebuilds the DerivedMesh, after which the materials weren't
applied any more (causing the default to the first material slot).
Note that some little parts of code have been dissabled because eval_ctx
was not available there. This should be resolved once DerivedMesh is
replaced.
No longer passing time as float and constructing ISampleSelectors all
over the place. Instead, just construct an ISampleSelector once and
pass it along.
Crash is due by mismatching loops and faces counts between the Alembic
data and the Blender derivedmesh which does not appear so
straightforward to fix (the crash happens deep in the derivedmesh code).
So for now, try to detect if the topology has changed and if so, both
only read vertices (vertex colors and UVs won't be read, as tied to face
loops) and add a warning message in the modifier's UI to let the user
know.
constraints.
This avoids traversing the archive everytime object data is needed and
gives an overall consistent ~2x speedup here with files containing
between 136 and 500 Alembic objects. Also this somewhat nicely de-
duplicates code between data creation (upon import) and data streaming
(modifiers and constraints).
The only worying part is what happens when a CacheFile is deleted and/or
has its path changed. For now, we traverse the whole scene and for each
object using the CacheFile we free the pointer and NULL-ify it (see
BKE_cachefile_clean), but at some point this should be re-considered and
make use of the dependency graph.
All in all, this patch adds an Alembic importer, an Alembic exporter,
and a new CacheFile data block which, for now, wraps around an Alembic
archive. This data block is made available through a new modifier ("Mesh
Sequence Cache") as well as a new constraint ("Transform Cache") to
somewhat properly support respectively geometric and transformation data
streaming from alembic caches.
A more in-depth documentation is to be found on the wiki, as well as a
guide to compile alembic: https://wiki.blender.org/index.php/
User:Kevindietrich/AlembicBasicIo.
Many thanks to everyone involved in this little project, and huge shout
out to "cgstrive" for the thorough testings with Maya, 3ds Max, Houdini
and Realflow as well as @fjuhec, @jensverwiebe and @jasperge for the
custom builds and compile fixes.
Reviewers: sergey, campbellbarton, mont29
Reviewed By: sergey, campbellbarton, mont29
Differential Revision: https://developer.blender.org/D2060
