The Alembic exporter has been restructured by leverages the
`AbstractHierarchyIterator` introduced by the USD exporter. The produced
Alembic files have not changed much (details below), as the Alembic
writing code has simply been moved from the old exporter to the new. How
the export hierarchy is handled changed a lot, though, and also the way
in which transforms are computed. As a result, T71395 is fixed.
Differences between the old and new exporter, in terms of the produced
Alembic file:
- Duplicated objects now have a unique numerical suffix.
- Matrices are computed differently, namely by simply computing the
evaluated transform of the object relative to the evaluated transform
of its export-parent. This fixes {T71395}, but otherwise should
produce the same result as before (but with simpler code).
Compared to the old Alembic exporter, Subdivision modifiers are now
disabled in a cleaner, more efficient way (they are disabled when
exporting with the "Apply Subdivisions" option is unchecked). Previously
the exporter would move to a new frame, disable the modifier, evaluate
the object, and enable the modifier again. This is now done before
exporting starts, and modifiers are only restored when exporting ends.
Some issues with the old Alembic exporter that have NOT been fixed in
this patch:
- Exporting NURBS patches and curves (see T49114 for example).
- Exporting flattened hierarchy in combination with dupli-objects. This
seems to be broken in the old Alembic exporter as well, but nobody
reported this yet.
Differential Revision: https://developer.blender.org/D7664
Reviewed By: Sergey
Thanks @mont29 for this patch.
This creates an explicit undo step after the Alembic importer has finished
running. This is necessary when the importer runs as a background job.
The `ABC_INLINE` macro has been in the Alembic code since it was introduced
to Blender in rB61050f75b13e. It basically does the same a `BLI_INLINE`,
though, so there is no need to keep it around.
This commit only moves code into the `blender::io::alembic` namespace,
it does not move `static` functions into an anonymous namespace.
No functional changes.
This moves most of the exporter-related code
from `source/blender/io/alembic/intern`
to `source/blender/io/alembic/exporter`
This is to prepare the Alembic code for the switchover to using
`blender::io::AbstractHierarchyIterator`. When that happens, a few more
files will be added, and having things in a separate 'exporter'
directory makes things less cluttered.
Note that exporting consists of multiple steps (determine export
hierarchy, create Alembic archive, and then write data into it), which
is why the directory is called "exporter", but many of the files are
called "writer".
No functional changes.
Blender now always exports transforms as as "inheriting", as Blender has
no concept of parenting without inheriting the transform.
Previously only objects with an actual parent were marked as
"inheriting", and parentless objects as "non-inheriting". However,
certain packages (for example USD's Alembic plugin) are incompatible
with non-inheriting transforms and will completely ignore such
transforms, placing all such objects at the world origin.
When importing non-inheriting transforms from Alembic, Blender will
break the parent-child relation and thus force the child to (correctly)
interpret the transform as world matrix.
Other types already had spaces, periods, and colons replaced by
underscores. The upcoming Alembic exporter (based on the
`AbstractHierarcyIterator` class) will be more consistent and apply the
same naming rules everywhere. This is in preparation for that change.
The `get_…_name()` functions in `abc_util.{cc,h}` will be removed then.
Previously the Alembic exporter exported a mesh object to
`{object.name}/{object.name}Shape`. Now it exports to
`{object.name}/{mesh.name}` instead. The same change also applies to
other object data types.
Note that the code now is a bit hackish, as `m_name` is set even in
cases where it isn't used. This hackishness was already there, though,
but it's now just more visible. This will all be cleaned up when the
Alembic exporter is ported to use the `AbstractHierarchyImporter`
structure of the Universal Scene Description (USD) exporter.
Reviewed By: mont29
Differential Revision: https://developer.blender.org/D7672
Alembic is not a single file format, it can be stored in two different
ways: Ogawa and HDF5. Ogawa replaced HDF5 and is smaller and much faster
(4-25x) to read ([source](http://exocortex.com/blog/alembic_is_about_to_get_really_fast)).
As long as Blender has had Alembic support, it has never supported the
HDF5 format in any release. There is a build option `WITH_ALEMBIC_HDF5`
that can be used to enable HDF5 support in your own build. This commit
removes this build option and the code that it manages.
In the years that I have been maintainer of Blender's Alembic code, I
only remember getting a request to support HDF5 once, and that was to
support very old software that has likely since then been updated to
support Ogawa. Ubuntu and Fedora also seem to bundle Blender without
HDF5 support.
This decision was discussed on
[DevTalk](https://devtalk.blender.org/t/alembic-hdf5-support-completely-remove)
where someone also mentioned that there is a tool available that can
convert HDF5 files to the Ogawa format.
- BKE_lattice_deform_data_create was init_latt_deform.
- BKE_lattice_deform_data_destroy was end_latt_deform.
- BKE_lattice_deform_data_eval_co was calc_latt_deform.
The file subversion is no longer used in the Python API or user interface,
and is now internal to Blender.
User interface, Python API and file I/O metadata now use more consistent
formatting for version numbers. Official releases use "2.83.0", "2.83.1",
and releases under development use "2.90.0 Alpha", "2.90.0 Beta".
Some Python add-ons may need to lower the Blender version in bl_info to
(2, 83, 0) or (2, 90, 0) if they used a subversion number higher than 0.
https://wiki.blender.org/wiki/Reference/Release_Notes/2.83/Python_API#Compatibility
This change is in preparation of LTS releases, and also brings us more
in line with semantic versioning.
Fixes T76058.
Differential Revision: https://developer.blender.org/D7748
This was caused by a side-effect of our exporting code's memory
management (Alembic considers data "written" and "final" when its C++
objects go out of scope) in combination with my change in
rB65574463fa2d. I removed an "only export UVs on the first frame" clause
because it was unclear why this restriction was there. As it turns out,
it breaks the export of the 2nd and subsequent UV maps on an animated
mesh. Effectively, on every frame the Alembic library thought we want to
create a new UV map, instead of continuing to write a new frame of data
to the existing one.
This is resolved by keeping a reference to the C++ objects for the UV
maps in memory while the exporter is running.
It is not impossible that the number of knots is stored wrong in the
file (for example, it will be 1 knot only).
This change fixes bad memory allocation and bad memory access in such
cases. It also fixes strict compiler warning which was mentioning that
the allocation size is wrong),
There isn't really the correct way of dealing with such situation, so
simply fall back to Blender's knots calculation.
Differential Revision: https://developer.blender.org/D7765
When auto-smooth enabled, but no custom normals layer present, the Alembic
exporter would incorrectly assume the mesh was shaded smooth. This is now
corrected, and normals are always written when auto-smooth is enabled.
In the Alembic importer, the animation of UVs and normals was
overlooked; when the mesh geometry is not animated, the entire mesh was
considered constant.
T76132 concerns both the exporting and importing of changing UVs. This
commit fixes the importing.
In the Alembic exporter, UVs were only exported on the first frame. This
is an issue, as when exporting an animated mesh the topology can change,
and then the UV coordinates of the first frame are no longer valid.
T76132 concerns both exporting and importing changing UVs. This fixes
the exporting.
Even though {T76514} is caused by invalid geometry, and thus technically
constitutes a bug in the software that created the Alembic file, I would
like Blender not to crash on importing such a file.
The error in the Alembic file consists of invalid mesh loops, where
consecutive loops refer to the same vertex. The `BKE_mesh_validate()`
can actually correct these errors, so this commit focuses on two things:
- Letting Blender survive the situation until the mesh is loaded, and
- Detecting the error so that `BKE_mesh_validate()` can be called only
when necessary. This ensures there is only a minimal impact on
performance when loading actually valid data.
Differential Revision: https://developer.blender.org/D7703
Reviewed By: JacquesLucke
Surrounding includes with an 'extern "C"' block is not necessary anymore.
Also that made it harder to add any C++ code to some headers, or include headers
that have "optional" C++ code like `MEM_guardedalloc.h`.
I tested compilation on linux and windows (and got help from @LazyDodo).
If this still breaks compilation due to some linker error, the header containing
the symbol in question is probably missing an 'extern "C"' block.
Differential Revision: https://developer.blender.org/D7653
The long-term goal is to move code out of `abc_util.{h,cc}` into either
files with better, more concrete names, or simply into the one file
where they are used.
No functional changes.
The `BKE_animsys.h` and `anim_sys.c` files already had a an "AnimData
API" section. The code in that section has now been split off, and
placed into `BKE_anim_data.h` and `anim_data.c`.
All files that used to include `BKE_animsys.h` have been adjusted to
only include the animation headers they need (sometimes none).
No functional changes.
The files are now split up into the following sections:
- `BKE_anim_path.h` and `anim_path.c` for path/curve functions.
- `BKE_anim_visualization.h` and `anim_visualizationanim_path.c` for
animation visualization (mostly motion paths).
- `BKE_duplilist.h` for DupliList function declarations. These were
already implemented in `object_dupli.c`, so they were rather out of
place being declared in `BKE_anim.h` in the first place.
No functional changes.
I've added a very minimal mesh validation before the Alembic mesh is actually
converted to a Blender mesh. This prevents a specific crash with an example
file attached to T74200.
In rB7c5a44c71f13 I changed the way transform matrices are loaded from
Alembic. Instead of having the Alembic importer convert matrices from
local (in the Alembic file) to World (to pass to the constraint handling
the animation of transforms), I set the constraint space to
`CONSTRAINT_SPACE_LOCAL`.
This worked thanks to rB7728bfd4c45c. However, that commit was reverted,
which meant that for parentless objects `CONSTRAINT_SPACE_LOCAL` no
longer means "local space".
The situation is resolved by setting the constraint to world space
again, and computing the world matrix in the Alembic importer.
This moves the `alembic`, `avi`, `collada`, and `usd` modules into a common
`io` directory.
This also cleans up some `#include "../../{somedir}/{somefile}.h"` by
adding `../../io/{somedir}` to `CMakeLists.txt` and then just using
`#include "{somefile}.h"`.
No functional changes.
