Refactor and revamp import and export of `UsdGeomNurbsCurves` prim
objects.
Fixes#130056, among other things.
Summary of changes and enhancements:
- Export:
- Write out `nurb_weight` attribute as the USD `pointWeights` primvar
- Properly write out cyclic NURBS curves data (* see notes)
- Import:
- Import using the new `Curves` datablock rather than the old `Curve`
- Properly read in cyclic NURBS curves data (* see notes)
- Tries harder to match incoming knot vector to standard `knots_mode`,
will use Custom otherwise
- Support import of all custom primvars and data attached to the prim
(for use with Geometry Nodes etc.) (* see notes)
Tests were added which check a variety of point count, order, knot_mode,
and cyclic combinations (generated through Geometry Nodes). A small
number of hand-crafted curves were used to test the Custom knots_mode
support on import. Additionally, the tests cover the case when there are
multiple curves defined for a single object.
Notes:
- Cyclic NURBS support is reliant on the current, under-spec'd, USD
documentation. Changes may be required in the future if/when the USD
spec is clarified: https://github.com/PixarAnimationStudios/OpenUSD/issues/3740
- Some Cyclic x knots_mode combinations are not correct and would
require more research to determine how to properly address.
- Custom attributes are not imported for Cyclic NURBS curves yet. Those
will require additional work to function correctly and are also
reliant on seeing how the USD spec changes.
Pull Request: https://projects.blender.org/blender/blender/pulls/143970
Found while trying to import an instanced point-instancer with the
operator setting `support_scene_instancing=false`.
The point-instancer Prototype would be partially processed but not
completely since the option was disabled. This caused a discrepancy
during the final portion of import where the view layer was synced and
we attempted to query for an object that was not present.
Pull Request: https://projects.blender.org/blender/blender/pulls/144845
The mesh importer was only checking for animated positions, velocities,
and primvars when determining if a cache modifier needed to be used.
Extend this to crease values (and normals) too.
The added test ensures a base level of coverage here.
Related to: #141633
Pull Request: https://projects.blender.org/blender/blender/pulls/141643
Adds a Point Instancing exporter based on the existing
USDPointInstancerReader. Covers both round-trip and Blender-native
workflows. Exports 'Instance on Points' setups as USDGeomPointInstancer,
supporting objects, collections, and nested prototypes.
A warning is shown during export if invalid prototype references are
detected. These would occur if an instancer attempts to instance itself.
This feature is currently gated behind an off-by-default export option
(`use_instancing`) as there are still a few cases which can yield
incorrect results.
Further details in the PR.
Ref: #139758
Authored by Apple: Zili (Liz) Zhou
Pull Request: https://projects.blender.org/blender/blender/pulls/139760
It is possible for a mesh to change topology across frames but still be
detected as not needing a topology update.
Until we can make a finer-grained check against the before and after
topology, unconditionally ensure it's updated for now.
Adds a new test that checks a few frames of changing topology that is
similar, but not the same.
Pull Request: https://projects.blender.org/blender/blender/pulls/140253
Handle the `DomeLight_1` schema for import and translate to a World
material like what was already done for the original `DomeLight` schema.
The primary difference is that the new schema provides a `poleAxis`
attribute that authoring applications can use to remove ambiguity for
the orientation of the HDRI texture. Some care was made to match
`usdview` with a set of hand-crafted files. However, after matching,
some real scenes ended up displaying differently. These were corrected
but this could mean there's still issues that will need investigation
and fixing in the future.
Co-authored-by: Nig3l <nig3lpro@gmail.com>
Co-authored-by: Jesse Yurkovich <jesse.y@gmail.com>
Pull Request: https://projects.blender.org/blender/blender/pulls/137761
It was intended that pointers instancers would be skipped if they were
marked as invisible. However, we didn't account for the case of an
instancer using the "inherits" visibility but one of its ancestors in
the hierarchy being invisible.
Now these instancers will also be excluded. This is done by checking for
purpose and visibility earlier and halting the recursive traversal as
soon as we find a prim which doesn't meet the criteria.
Pull Request: https://projects.blender.org/blender/blender/pulls/139241
Add support for the UsdPrimvarReader_TYPE templates for both import and
export. These are used by several USD test assets and support here
represents the last major piece of the UsdPreviewSurface spec to be
implemented.
On import these become `Attribute` nodes and on export the `Attribute`
nodes will become `UsdPrimvarReader_TYPE`'s accordingly.
Import:
- `UsdPrimvarReader_float` and `UsdPrimvarReader_int` will use the `Fac`
output
- `UsdPrimvarReader_float3` and `UsdPrimvarReader_float4` will use the
`Color` output
- `UsdPrimvarReader_vector`, `UsdPrimvarReader_normal`, and
`UsdPrimvarReader_point` will use the `Vector` output
Export (only `Geometry` Attribute types are considered):
- `Fac` will use `UsdPrimvarReader_float`
- `Color` will use `UsdPrimvarReader_float3`
- `Vector` will use `UsdPrimvarReader_vector`
- `Alpha` is not considered
MaterialX note:
Hydra-native support is a bit more involved and will have to be done
separately. Hydra w/USD sync is trivial to implement but those changes
have been left out here.
Pull Request: https://projects.blender.org/blender/blender/pulls/135143
This change moves the tests data files and publish folder of assets
repository to the main blender.git repository as LFS files.
The goal of this change is to eliminate toil of modifying tests,
cherry-picking changes to LFS branches, adding tests as part of a
PR which brings new features or fixes.
More detailed explanation and conversation can be found in the
design task.
Ref #137215
Pull Request: https://projects.blender.org/blender/blender/pulls/137219
