This PR adds the following changes:
A single root is always set as default. After talking to Wave and
Spiff, we settled on root being the best default. Users who don't
want a single root prim inserted, can choose to clear the field
The root prim no longer requires the user to prefix the field with /.
It will implicitly insert that for them.
On export, the root_prim hierarchy is now defined all as Xform
instead of just the final prim in the path. Each prim also has
custom metadata added to show that it was generated by Blender.
This follows convention in other DCCs as well.
On import, the code now finds the hierarchy of generated prims
using that metadata. It then skips importing them. This means that
you can roundtrip hierarchies even with an inserted root.
Co-authored-by: Dhruv Govil <dgovil2@apple.com>
Pull Request: https://projects.blender.org/blender/blender/pulls/113187
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.
This PR addresses issue “USD export does not respect opacity threshold for clip alpha blend mode #107062”
This commit extends the USD Preview Surface material support to author the opacityThreshold attribute of materials on export, when the Alpha Clip blend mode is selected.
When authoring alpha cutouts in Blender, one sets the Blend Mode to "Alpha Clip", and the Clip Threshold to some value greater than zero.
When this case is detected on export, we now author the opacityThreshold attribute to match the specified clip threshold.
Note that opacityThreshold is already handled correctly on import, so this change allows the feature to be fully round-tripped.
Co-authored-by: Matt McLin <mmclin@apple.com>
Pull Request: https://projects.blender.org/blender/blender/pulls/107149
A properly authored USD file will have the extent attribute authored on all prims conforming to UsdGeomBoundable.
This cached extent information is useful because it allows the 3D range of prims to be quickly understood without reading potentially large arrays of data. Note that because the shape of prims may change over time, extent attributes are always evaluated for a given timecode.
This patch introduces support for authoring extents on meshes and volumes during export to USD.
Because extents are common to multiple kinds of geometries, the main support for authoring extents has been placed in USDAbstractWriter, whose new author_extent method can operate on any prim conforming to pxr::UsdGeomBoundable. The USD library already provides us the code necessary to compute the bounds for a given prim, in pxr::UsdGeomBBoxCache::ComputeLocalBound.
Note that not all prims that are imageable are boundable, such as transforms and cameras.
For more details on extents, see https://graphics.pixar.com/usd/release/api/class_usd_geom_boundable.html#details.
Note that when new types of geometries are introduced, such as curves in https://developer.blender.org/D16545, we will need to update the USD writer for that geometry such that it calls this->author_extent.
Update on Feb 2: This patch has been updated to include a unit test to ensure authored extents are valid. This test requires new test assets that will need to be submitted via svn. The test assets are attached in the d16837_usd_test_assets.zip file. To use, unzip and merge the contents of this zip into the lib/tests/usd folder.
This unit test also addresses #104269 by validating compliance of exported USD via UsdUtils.ComplianceChecker.
Pull Request #104676
Michael B Johnson
Campbell Barton
Hans Goudey