Blender Git Loki

USD Import: Formatting fixes.

USD Import: Convert to Z Up option.

Added a Convert to Z Up import option and logic to rotate
imported root objects 90 degrees about the X-axis if this
option is checked and the USD stage up-axis is Y.

USD Import: Scale option fixes.

Updated the code to apply the global scale option, which
was previously ignored. Fixed application of global scale
in the xform reader matrix calculation to only apply the
scale to root objects. Also fixed bug in setting the
is_constant flag and simplified some of the code.

USD Import format fixes.

USD Import: made USDPrimReader destructor virtual.

USD Import: USD Preview conversion.

Added experimental Import USD Preview option to convert
UsdPreviewSurface shaders to Principled BSD shader networks,
for an approximate preview. Added new USDMaterialReader
class, which implements this feature. Also added a
Set Material Blend option to automatically set the material
blend method based on the UsdPreviewSurface shader's opacity
and opacityThreshold inputs. Finally, updated the logic so that
no materials will be imported if the Materials option is
not checked.

USD Import: USDPrimReader uninitialized members.

Fixed bug where several USDPrimReader class member variables
were not being intialized in the constructor. One of the
previously uninitialized variables stores the reference count,
which was causing memory leaks in some cases.

USD Import: UV fixes.

Made the following updates to fix UV import errors:
Added logic to read UVs with Vertex interpolation and
indexed UVs. Fixed incorrect UV winding order for
left-handed orientation.

USD Import: Minor instancing fixes.

Small edit to the Instancing import option parameter
description. Now allowing setting null instance collection
on USDInstanceReader objects.

Formatting fixes.

USD Import: support instance collections.

Added an experimental Instancing option to support
importing USD scenegraph instances as Blender
instanced collections.

USD Importer: dependency graph update crash.

Fixed occasional random crash due to simultaneous update
to the dependency graph from multiple threads. A typical
collision might happen when the USD import job thread
is creating a material while the window manager in the
main thread is processing event notifiers. The current
fix is to remove the ND_FRAME flag from the call to
WM_jobs_timer(), which prevents ED_update_for_newframe()
from being called from wm_event_do_notifiers().

USD import: uniform interpolation normals.

Added logic to import USD normals with uniform interpolation
(i.e., per-face normals) as Blender loop normals.

USD import: convert UsdGeomImageables only.

Currently, the importer converts every node in the USD
to a Blender Empty object by default, including nodes
that aren't of UsdGeomImageable type, such as materials
and shaders. This can unnecessarily bloat the Blender
scene with nodes that are not immediately useful. I've
added logic to restrict conversion to nodes that are
UsdGeomImageables, and this can have a dramatic effect
in some cases. For exmaple, the number of nodes imported
in the Attic scene is reduced from 1,025 to 238 with
this change.

USD import: xform cache constraint parenting bug.

USD_get_transform() was not taking the object's parent
transform into account. Now following the same logic
as in the corresponding Alembic implementation,
ABC_get_transform(), to fix this.

USD Import: Visible Prims Only flag.

Added new option to prune primitives by visibility.
If this option is enabled, invisible prims will
be excluded from the traversal. This only applies
to prims with a non-animating visibility attribute.
Prims with animating visibility will always be imported.

Apply orientation when importing USD normals.

Also added check to ensure normal and loop counts match.

USD import: orientation bug.

Uninitialized USDMeshReader::m_isLeftHanded flag was
causing the vertex winding orientation to randomly flip,
causing incorrect shading and other issues.

USD import: handle primvars:normals if specified.

Per Pixar UsdGeomPointBased documentation: If 'normals' and
'primvars:normals' are both specified, the latter has precedence.

USD import: Handle empty vertex-varying normals.

If point normals are empty, now invoking BKE_mesh_calc_normals()
to avoid black renders. Since BKE_mesh_calc_normals() requires
edges to be defined, moving point normal calculation to follow
reading polys.