Change Log

[0.7.2] - 2016-12-02

Added ability to apply a custom prefix to shared library names by specifying the PXR_LIB_PREFIX option to CMake.
Added ability to disable tests by using the PXR_BUILD_TESTS option with CMake.
usddiff can now diff two directories containing USD files.
Value clips on a prim may now be specified using 'template' clip metadata. This is a more compact representation for simple cases where each value clip corresponds to a single time code.
Better support for non-file-backed asset resolution
- Made ArDefaultResolver public, so that subclasses can layer behavior on top of it.
- Added ArResolver API for retrieving files from data store when needed.
Initial version of UsdGeomPointInstancer schema and preliminary support in usdImaging.
pxrUsdReferenceAssemblies in Maya can now import animation from a USD scene. See http://openusd.org/docs/Maya-USD-Plugins.html#MayaUSDPlugins-ImportingasAssemblies for details.
Core USD metadata (e.g. hidden, instanceable, kind) now roundtrips through Maya, stored as "USD_XXX" attributes on corresponding Maya nodes.

Removed dependency on Qt. Note that PySide is still a dependency for usdview.
- Removed imaging/glfq library as part of this work.
Modified variant behavior in composition:
- Variants may now be nested within other variants in scene description. Nested variants may be authored by using nested UsdEditContext objects returned by UsdVariantSet::GetVariantEditContext.
- Weaker variants may now introduce variant selections that affect stronger variants. Previously, these selections would be ignored and the variant fallbacks would be used instead.
Optimized .usdc file format performance in certain cases:
- Output is buffered in memory to improve write times for layers containing many nested dictionaries. In one such example, wall-clock time improved by ~64% and system time improved by 89%.
- Time samples are now written out grouped by time to improve read performance for frame-by-frame access patterns.
Several optimizations to improve USD scenegraph authoring and composition speed and reduce memory consumption. In some use cases, we observed:
- ~5-7x less memory consumed by Pcp dependency tracking structures
- ~40% less time spent to author large stages
Exporting USD from the Maya Export window now produces binary .usd files by default instead of .usda files.

Fixed bug where edits to a layer opened in Maya would persist when reopening that layer in a new scene.
Fixed issue where exporting USD from the Maya Export window would produce files ending with ".usda", even if a different format was specified. The exporter should now respect any extension that is entered, so long as the "Default file extensions" option is turned off.
Fixed several issues with example plugins being improperly built, making them unusuable, and missing functionality.
Various other bug fixes and performance improvements.

UsdMaterial schema for shading, intended to replace UsdLook. Also added support for this new schema to Hydra.
Initial version of UsdUI schema library, intended for encoding GUI information on USD prims.
Parallel teardown of some data members in UsdStage, speeding up overall teardown by ~2x.
Support for packed vertex normals to Hydra, reducing GPU memory consumption by 20-30% in some cases.
Ability to compare two composed stages to usddiff by specifying the "--compose" or "-c" options.
Support for soft-selection for collapsed USD assemblies in Maya.
Support for exporting color sets and UV sets as indexed primvars from Maya.

Refactored Hydra libraries to move higher-level concepts out of the core hd library and into hdx.
Removed use of opensubdiv3/ include path from imaging code in favor of standard opensubdiv/ include.
Modified UsdStage to automatically load newly-discovered payloads if their nearest ancestor's payload was also loaded. For example, consumers will no longer have to explicitly call UsdStage::Load to ensure payloads are loaded when switching variants on a prim, so long as their nearest ancestor is also loaded.
Refactoring and other changes to help with Mac and Windows ports.
Updated doxygen and other documentation.

Fixed issue that caused Alembic plugin (usdAbc) to be misconfigured at build time, which required users to manually update its plugInfo.json and set an environment variable at runtime to make it work. This plugin is now installed to $PREFIX/plugin/usd/ and requires no additional steps to use once it has been built.
Fixed issue with .usdc files that resulted in corrupted files on Windows. The file structure was changed, so the .usdc version has been bumped from 0.0.1 to 0.1.0. USD will continue to write 0.0.1 files by default, but will begin writing 0.1.0 files in the near future.

Users may choose to write files with the new version immediately by setting the environment variable USD_WRITE_NEW_USDC_FILES_AS_VERSION to "0.1.0".

Note that 0.0.1 files are still readable using this release, except for those that have been generated on Windows using 0.7.0. Early testers on Windows will need to regenerate those files with this release.
Fixed issue that caused usdGenSchema to generate files that could not be compiled.
Added a workaround for TBB-related issue in Maya that caused hangs when using the USD Maya plugin. This can be enabled at build time by specifying the PXR_MAYA_TBB_BUG_WORKAROUND option to CMake.
Various other bug fixes and performance improvements.

Initial release