This enables material displacement for UsdPreviewSurface import and
export. Scenarios are limited by what's supported by the preview surface
itself. Namely only Object Space displacement can be used (no vector
displacement)[1] and the Midlevel and Scale parameters are maintained by
adjusting the scale-bias on the image texture controlling the Height
(this means that Midlevel and Scale must be constants).
Hydra/MaterialX support is more complicated. First, there is a bug which
prevents scalar displacment from working correctly and that needs USD
2408+ for the fix[2]. Second, is that there's an open question about
which coordinate system to use for MaterialX's vector displacement maps.
Lastly, Hydra GL does not render displacement, making verification using
only Blender impossible[3]. As a result, this PR only makes MaterialX
"ready" for support, but stops short of actually connecting the final
piece of the node graph until more of the above can be sorted out.
Tests are added which cover:
- Variations of Midlevel and Scale values
- A constant Height setup
- Negative scenarios checking that only Object space is supported
and that midlevel and scale need to be constants
[1] https://openusd.org/release/spec_usdpreviewsurface.html
[2] https://github.com/PixarAnimationStudios/OpenUSD/issues/3325
[3] https://forum.aousd.org/t/materialx-displacement-hydra-storm/1098/2
Pull Request: https://projects.blender.org/blender/blender/pulls/128909
In March 2022 this was added as a provision to check/guard the build if
external folks were compiling without USD "Imaging" support [1]
In Feb 2023 code was added which ended up depending on "Imaging"
unconditionally (and probably more at this point) [2]
Since we haven't heard this being a problem so far, and because the USD
build option is enabled by default, let's just remove it.
The test which was added is also removed because the main import/export
code serves as the compile test, and the python test code serves as a
much more sufficient check of actual functionality.
[1] https://archive.blender.org/developer/D14456
[2] Commit `72a85d976a5781a21166356b24668b8c48d51690`
Pull Request: https://projects.blender.org/blender/blender/pulls/129733
Removes the last remaining, direct, usage of streams inside USD.
CLOG is not used here because there's no way to have a trace be "always
printed," even if using a log-level of -1 or similar.
Pull Request: https://projects.blender.org/blender/blender/pulls/129702
For C/C++ doc-strings should be located in headers,
move function comments into the headers, in some cases merging
with existing doc-strings, in other cases, moving implementation
notes into the function body.
The existing Volume export, which already supports VDB file sequences
and static volumes created inside Blender, is now extended to handle
dynamically created and modified volumes. This allows scenarios where a
Volume Displace modifier is placed over-top an existing VDB sequence or
when Geometry Nodes is used to create animated volumes procedurally.
Detection of what counts as animation is simplistic and mimics what has
been used for Meshes. Essentially if there are any modifiers on the
volume we assume that the volume is "varying" in some way. This can lead
to situations where new volume files are written unnecessarily.
Volume import was also adjusted to correctly set the sequence "offset"
value. This is required to properly handle the case when a VDB sequence
begins animating at a different frame than what's implied by the file
name. For example, a VDB file sequence with file names containing 14-19
but the user wants to animate on frames 8-13 instead.
Tests are added which cover:
- Animated VDB file sequences
- Animated Mesh To Volume where the mesh has been animated
- Animated Volume Displacement where displacement settings are animated
- Animated Volumes created with a Geometry Nodes simulation
----
New test data has been checked in: `tests/data/usd/usd_volumes.blend` and files inside `tests/data/usd/volume-data/`
Pull Request: https://projects.blender.org/blender/blender/pulls/128907
It was difficult to notice, but we weren't making use of the
`USDPrimReader::valid()` API calls during import.
In many(all?) cases this was fine as we would check the validity during
`read_object_data` or similar anyhow. Rather than just removing the API
entirely, this patch attempts to use it and has the following design:
- Where ever and whenever a reader is created, in addition to checking
null, we should now also check for `valid()` This happens in
`usd_capi_import` and `usd_reader_stage`.
- The `valid()` call is intended to check just the USD object status.
Blender object checks are handled elsewhere (same as they are
currently) since these objects are often not available at the time of
the call to `valid()`
This has the benefit that we at least know that USD is valid before our
heavy reading code ever starts executing. Some duplicate checks are now
removed.
Pull Request: https://projects.blender.org/blender/blender/pulls/129181
The `fmtlib` text formatting library, when compiled in C++20 onwards,
requires that the incoming format string is a compile-time constant so
it's able to perform type checks against it[1]. The change here ensures
it can do so.
While we're not set to go to C++20 any time soon, this is a backwards
compatible change that can be done today and allows us to focus on the
harder fmt-related issues later.
No change in performance or functionality was observed.
[1] https://godbolt.org/z/qG5dsf7YG
Pull Request: https://projects.blender.org/blender/blender/pulls/129272
Removes unused GPv2 functions in blenkernel.
Notes:
- Functions for layer masks are still in use, but annotations never
have layer masks in the first place. Would be good to remove the data
structures so we can remove the functions too.
- Some multi-frame edit functions are also still nominally used, but
multi-frame editing is not an active feature for annotations. This
should also be removed.
Pull Request: https://projects.blender.org/blender/blender/pulls/128709
During stage load we first look for Prototype prims which are used for
instancing. However, if the instancer itself at the root of that
Prototype hierarchy would later be excluded because of either purpose or
visibility checks, the Prototypes would still be processed. These would
correctly be imported but would end up orphaned because nothing would
later add them to the view layer. Code expecting these objects to be
found within the scene would then fail.
In Animal Logic ALab this situation played out where there was a
`/root/instancer` prim with purpose "render" and we proceeded to load
the prims under the `/root/instancer/Prototypes/...` hierarchy. Since we
were attempting to load just the "proxy" purpose, the `/root/instancer`
was later excluded and the orphaning of those prototypes happened.
The change here moves `collect_point_instancer_proto_paths` to a method
of `USDStageReader` so it can now access `include_by_purpose` and
`include_by_visibility`. And these are now used to prevent unnecessary
Prototype loading.
Pull Request: https://projects.blender.org/blender/blender/pulls/128564
Follow-up to #128061, which addressed the export side of this.
This updates the Collada import code to import properly to slotted
actions.
Note that importing the animation of non-transform properties (e.g.
camera fov, material colors, lamp intensity, etc) does not work,
but that isn't caused by this PR. That was already not working at
least as far back as Blender 3.6.5.
Pull Request: https://projects.blender.org/blender/blender/pulls/128529
USD has the concept of material "purposes" which allows different
materials to be associated for a prim and gives special meaning to them.
These are somewhat similar to display purposes, which we already allow
to be chosen, but are distinct concepts. This PR adds an option for
Import allowing the user to chose which material purpose to load.
Blender currently attempts to load purposes automatically. It starts
with "allPurpose" and then moves to "preview" and "full" in that order.
This behavior is now changed and the automated search is removed to
instead give the user control which purpose to load. Additionally, USD
already has its own fallback behavior during material resolution[1]:
- When given "full" it will first check "full" and fallback to
"allPurpose" if not found. An additional, Blender-specific fallback
to "preview" is also implemented here upon request.
- When given "preview" it will first check "preview" and fallback to
"allPurpose" if not found
- When given "allPurpose", it will only check "allPurpose"
I have opt'd to keep this behavior directly as-is to not introduce
differences that may surprise those already familiar with USD elsewhere.
Additionally, I've set Blender's default import purpose to "full" to
ensure we're loading in the highest quality assets first. Though this
has the obvious risk that "full" assets tend to be quite heavy. We can
change to "preview" if this proves too problematic later.
This does not change how Blender exports materials. Blender always uses
the "allPurpose" binding when writing its USD files.
--------
[1] USD docs:
https://openusd.org/release/api/class_usd_shade_material_binding_a_p_i.html#detailshttps://openusd.org/release/api/class_usd_shade_material_binding_a_p_i.html#UsdShadeMaterialBindingAPI_MaterialResolution
Pull Request: https://projects.blender.org/blender/blender/pulls/128206
When using the `create_collection` parameter during import, the newly
created Collection would be assigned a fake user which isn't necessary
and caused the user count to be 2 instead of the more natural 1 here.
Remove the fake user and add test coverage for the scenario in general.
Pull Request: https://projects.blender.org/blender/blender/pulls/128348
Wrong `points_num` when resizing the `CurvesGeometry`.
Otherwise, any attriute span will have wrong size, this triggers crash
when writing value in these attribute spans.
Pull Request: https://projects.blender.org/blender/blender/pulls/128472
When attempting to cache a generated image, the ImageFormatData's
view_settings would inadvertently be leaked due to the settings being
assigned a different set of values without first being free'd.
Additionally, there was another missed free from an early return a bit
later in the same function.
Pull Request: https://projects.blender.org/blender/blender/pulls/128229
This improve the API in multiple aspects:
* No need for an additional `lookup` call to get the current attribute. This
would internally iterate over all attributes again. This leads to O(n^2)
behavior. Note that there are still other reasons for O(n^2) behavior when
processing attributes (where n is the number of attributes).
* Remove the need to return a value from the iteration code to indicate that the
iteration should continue. This is now the default behavior. The iteration can
still be stopped by calling `iter.stop()`.
* Easier access to `is_builtin` property.
* Iterator callback only has a single parameter instead of two (of which one is
sometimes unused).
Pull Request: https://projects.blender.org/blender/blender/pulls/128128
Color primvars/attributes were historically treated as a special case
for both import and export. This was mostly done to align with how
painting and viewport display works in Blender. Export would generally
ignore color attributes except when they were found on a Mesh's Point or
FaceCorner domains. And import went out of its way to map incoming color
primvars to the FaceCorner domain in more situations than necessary.
To facilitate better roundtripping in Blender<=>USD workflows, and to
reduce code duplication, this PR teaches the common attribute utilities
how to handle color types. The color attributes will now work on all
relevant Mesh and Curve domains.
There were tests in place for this already but they were set to verify
the inverse state, i.e. the technically broken state, until this could
be fixed.
There remains one special case: "displayColor" primvars and attributes.
The "displayColor" is a special primvar in USD and is the de-facto way
to set a simple viewport color in that ecosystem. It must also be a
color3f type. In order to not regress import, if a "displayColor"
primvar is found on the Face domain we will map it to FaceCorner instead
so it can be displayed in the viewport; which has been the case for the
past several releases. We can drop this special-case if/when Blender can
display Face colors through the Viewport Shading "Attribute" color type.
Additionally, Blender will export this, and only this, color attribute
as a color3f.
Note: As was the case prior to this PR, the following 2 discrepancies
still prevent "perfect" round-trips:
- USD does not have an equivalent to Blender's byte colors; they are
treated as float during IO
- Blender does not have an equivalent to USD's color3 types; they are
treated as color4 during IO
Pull Request: https://projects.blender.org/blender/blender/pulls/127784
The collada export code was directly using `action->curves` in its
export code, which doesn't work with slotted actions. This commit
updates that code to use wrapper functions that provide access to the
correct fcurves regardless of whether the action is slotted or not.
Note that the import code has not yet been updated, and is left for
a future PR.
Ref: #123424
Pull Request: https://projects.blender.org/blender/blender/pulls/128061
Because we're moving to layered actions, which don't store their
fcurves in a list base, we need to update the places that assume the old
listbase-based structure.
This commit addresses the low-hanging fruit where code was previously
using the `LISTBASE_FOREACH` macro on a listbase of fcurves and it was
fairly obvious how to correctly update the code with minimal changes.
Other cases that either weren't immediately obvious or required
non-trivial code changes (or both) have been left for future PRs.
Additionally, uses of the list base that didn't use `LISTBASE_FOREACH`
were not investigated as part of this PR, whether trivial to update or
not.
Ref: #123424
Pull Request: https://projects.blender.org/blender/blender/pulls/127920
- Use `lookup_or_add_for_write_only_span` in more places
- Use `copy_from` when reading in positions for the few readers where
this wasn't already being done
- Remove manual memory management when processing corner normals
Pull Request: https://projects.blender.org/blender/blender/pulls/128043
