http://www.miikahweb.com/feed.php MiikaHweb - Blender Temp-sybren-usd-patch-02 Branch http://www.miikahweb.com/ MiikaHweb - Blender Temp-sybren-usd-patch-02 Branch fi Sun, 17 Jan 21 12:36:35 +0000 MiikaHweb RSS contact at miikahweb.com <![CDATA[[745a795]: USD: mark the exporter as Experimental feature]]> http://www.miikahweb.com/en/blender/git-logs/commit/745a795e46e510fd69aea3eae85991dee8b1f768 745a795
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
USD: mark the exporter as Experimental feature

This will allow us to merge the USD exporter into master before it's
completely finished.

----------------------------------------
4 Paths Changed]]>
Thu, 12 Dec 2019 11:35:30 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/745a795e46e510fd69aea3eae85991dee8b1f768Sybren A. Stüvel
<![CDATA[[01f5aa7]: USD: Report progress on a frame basis and with less guesswork...]]> http://www.miikahweb.com/en/blender/git-logs/commit/01f5aa7e015c9c803e6cc0e80bf8944652756709 01f5aa7
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
USD: Report progress on a frame basis and with less guesswork

----------------------------------------
1 Path Changed]]>
Wed, 11 Dec 2019 16:22:08 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/01f5aa7e015c9c803e6cc0e80bf8944652756709Sybren A. Stüvel
<![CDATA[[63a4e0c]: USD: set Linux-specific #define only on Linux]]> http://www.miikahweb.com/en/blender/git-logs/commit/63a4e0cefb6571e9fcfc01348190d2881c789b88 63a4e0c
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
USD: set Linux-specific #define only on Linux

----------------------------------------
1 Path Changed]]>
Wed, 11 Dec 2019 16:14:14 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/63a4e0cefb6571e9fcfc01348190d2881c789b88Sybren A. Stüvel
<![CDATA[[035cf7c]: USD: Fix exporting of meshes of dupli-objects]]> http://www.miikahweb.com/en/blender/git-logs/commit/035cf7c208a81482145eccdb561b1e71a13668ea 035cf7c
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
USD: Fix exporting of meshes of dupli-objects

The dupliobject's `base_flag` variable needed to be copied from its
duplicator.

----------------------------------------
9 Paths Changed]]>
Wed, 11 Dec 2019 15:34:30 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/035cf7c208a81482145eccdb561b1e71a13668eaSybren A. Stüvel
<![CDATA[[0a81d53]: Cleanup: USD: clarified a comment]]> http://www.miikahweb.com/en/blender/git-logs/commit/0a81d53ba6a0e0f6056595bd6bf0ba62d0e859a5 0a81d53
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
Cleanup: USD: clarified a comment

----------------------------------------
1 Path Changed]]>
Wed, 11 Dec 2019 15:34:30 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/0a81d53ba6a0e0f6056595bd6bf0ba62d0e859a5Sybren A. Stüvel
<![CDATA[[160ba6e]: USD: patch USD to allow Blender to construct a path to JSON...]]> http://www.miikahweb.com/en/blender/git-logs/commit/160ba6e58c746f34282228b807332fd02d5bff33 160ba6e
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
USD: patch USD to allow Blender to construct a path to JSON files

USD requires some JSON files, and it uses a static constructor to
determine the possible filesystem paths to find those files. This made
it impossible for Blender to pass a path to the USD library at runtime,
as the constructor would run before Blender's main() function. We have
patched USD (see usd.diff) to avoid that particular static constructor,
and have an initialisation function instead.

----------------------------------------
4 Paths Changed]]>
Wed, 11 Dec 2019 15:34:30 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/160ba6e58c746f34282228b807332fd02d5bff33Sybren A. Stüvel
<![CDATA[[23f51eb]: USD: private indicators]]> http://www.miikahweb.com/en/blender/git-logs/commit/23f51eb4bbd893ec5a57b199a099ea6278ee1981 23f51eb
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
USD: private indicators

No functional changes.

----------------------------------------
5 Paths Changed]]>
Wed, 11 Dec 2019 15:34:30 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/23f51eb4bbd893ec5a57b199a099ea6278ee1981Sybren A. Stüvel
<![CDATA[[32cd311]: USD: remove `PXR_PLUGINPATH_NAME` when testing]]> http://www.miikahweb.com/en/blender/git-logs/commit/32cd311fbaec10c3e33e4fad16bd2740a5176ef4 32cd311
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
USD: remove `PXR_PLUGINPATH_NAME` when testing

----------------------------------------
1 Path Changed]]>
Wed, 11 Dec 2019 15:34:30 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/32cd311fbaec10c3e33e4fad16bd2740a5176ef4Sybren A. Stüvel
<![CDATA[[394d192]: USD: pass data from invoke() to execute() in a struct]]> http://www.miikahweb.com/en/blender/git-logs/commit/394d1928b3902745f58a4eff23aecc19db1c91e6 394d192
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
USD: pass data from invoke() to execute() in a struct

This makes the code somewhat more complex, but more explicit and
future-proof as well.

----------------------------------------
1 Path Changed]]>
Wed, 11 Dec 2019 15:34:30 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/394d1928b3902745f58a4eff23aecc19db1c91e6Sybren A. Stüvel
<![CDATA[[3b4943b]: USD: moved all code into C++ namespace 'USD']]> http://www.miikahweb.com/en/blender/git-logs/commit/3b4943b2c6a1d0f066191d0b235a4b80a6a087ef 3b4943b
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
USD: moved all code into C++ namespace 'USD'

----------------------------------------
20 Paths Changed]]>
Wed, 11 Dec 2019 15:34:30 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/3b4943b2c6a1d0f066191d0b235a4b80a6a087efSybren A. Stüvel
<![CDATA[[481375f]: USD: removed the #include "BLI_iterator.h" from DEG_depsgraph_query...]]> http://www.miikahweb.com/en/blender/git-logs/commit/481375f756a85a03d8888750cbfe23a90cf250c3 481375f
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
USD: removed the #include "BLI_iterator.h" from DEG_depsgraph_query.h

This change has been committed to master.

----------------------------------------
1 Path Changed]]>
Wed, 11 Dec 2019 15:34:30 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/481375f756a85a03d8888750cbfe23a90cf250c3Sybren A. Stüvel
<![CDATA[[4a364b3]: USD: properly mark unused variable]]> http://www.miikahweb.com/en/blender/git-logs/commit/4a364b3caac9ca88c21b06813e3d230408c852ea 4a364b3
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
USD: properly mark unused variable

----------------------------------------
1 Path Changed]]>
Wed, 11 Dec 2019 15:34:30 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/4a364b3caac9ca88c21b06813e3d230408c852eaSybren A. Stüvel
<![CDATA[[64a4c1a]: USD: added note about upstream pull request for PXR_BUILD_USD_TOOLS...]]> http://www.miikahweb.com/en/blender/git-logs/commit/64a4c1a5e9ce92d50e9bd9d70048679126810a10 64a4c1a
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
USD: added note about upstream pull request for PXR_BUILD_USD_TOOLS

----------------------------------------
1 Path Changed]]>
Wed, 11 Dec 2019 15:34:30 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/64a4c1a5e9ce92d50e9bd9d70048679126810a10Sybren A. Stüvel
<![CDATA[[6e87612]: Depsgraph: add missing #include to DEG_depsgraph_query.h]]> http://www.miikahweb.com/en/blender/git-logs/commit/6e87612da83f103b8e4ec55d73b3a1067f25b6b9 6e87612
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
Depsgraph: add missing #include to DEG_depsgraph_query.h

The `DEG_depsgraph_query.h` file uses the `ITER_BEGIN` and `ITER_END`
macros defined in `BLI_iterator.h` without including that header.

No functional changes.

----------------------------------------
1 Path Changed]]>
Wed, 11 Dec 2019 15:34:30 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/6e87612da83f103b8e4ec55d73b3a1067f25b6b9Sybren A. Stüvel
<![CDATA[[70d9e57]: USD: Store BKE_main_blendfile_path(bmain) in a variable]]> http://www.miikahweb.com/en/blender/git-logs/commit/70d9e57aced59f55d22e63068b5f51ac4fb096ca 70d9e57
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
USD: Store BKE_main_blendfile_path(bmain) in a variable

----------------------------------------
1 Path Changed]]>
Wed, 11 Dec 2019 15:34:30 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/70d9e57aced59f55d22e63068b5f51ac4fb096caSybren A. Stüvel
<![CDATA[[857e549]: USD: no more fatal message in FindUSD.cmake]]> http://www.miikahweb.com/en/blender/git-logs/commit/857e549eabb875fb98d7593e0a21cf42c299bf2a 857e549
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
USD: no more fatal message in FindUSD.cmake

Instead of breaking the build, it properly sets `USD_FOUND` to `FALSE`.

----------------------------------------
1 Path Changed]]>
Wed, 11 Dec 2019 15:34:30 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/857e549eabb875fb98d7593e0a21cf42c299bf2aSybren A. Stüvel
<![CDATA[[918afc8]: USD: Avoid potential conflict with 2nd USD library]]> http://www.miikahweb.com/en/blender/git-logs/commit/918afc838eb8a5b6392bfe0063d2abc4368132c1 918afc8
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
USD: Avoid potential conflict with 2nd USD library

We now build the USD library with
`-DPXR_SET_INTERNAL_NAMESPACE=usdBlender`, which replaces the default
namespace `pxrInternal_v_x_y` with `usdBlender`. This is a preventative
measure that avoids possible conflicts when add-ons try to load another
USD library into the same process space.

----------------------------------------
1 Path Changed]]>
Wed, 11 Dec 2019 15:34:30 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/918afc838eb8a5b6392bfe0063d2abc4368132c1Sybren A. Stüvel
<![CDATA[[ce9b046]: USD: use LISTBASE_FOREACH]]> http://www.miikahweb.com/en/blender/git-logs/commit/ce9b0468fd3b9e2098453ff981b3c09f71e6503e ce9b046
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
USD: use LISTBASE_FOREACH

No functional changes.

----------------------------------------
1 Path Changed]]>
Wed, 11 Dec 2019 15:34:30 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/ce9b0468fd3b9e2098453ff981b3c09f71e6503eSybren A. Stüvel
<![CDATA[[dacef59]: USD: install libusd_m.a from usd.cmake instead of from harvesting...]]> http://www.miikahweb.com/en/blender/git-logs/commit/dacef592995773047e63aeab5e4b9b4e0ab5d550 dacef59
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
USD: install libusd_m.a from usd.cmake instead of from harvesting step

----------------------------------------
2 Paths Changed]]>
Wed, 11 Dec 2019 15:34:30 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/dacef592995773047e63aeab5e4b9b4e0ab5d550Sybren A. Stüvel
<![CDATA[[df153fc]: USD: clarified comment about defining _GLIBCXX_PERMIT_BACKWARD_HASH...]]> http://www.miikahweb.com/en/blender/git-logs/commit/df153fc331da165c0fa8eb480ea209489a722609 df153fc
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
USD: clarified comment about defining _GLIBCXX_PERMIT_BACKWARD_HASH

----------------------------------------
1 Path Changed]]>
Wed, 11 Dec 2019 15:34:30 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/df153fc331da165c0fa8eb480ea209489a722609Sybren A. Stüvel
<![CDATA[[e0c546e]: USD: renamed 'xform' to 'transform']]> http://www.miikahweb.com/en/blender/git-logs/commit/e0c546e45a821e8d353cd1841d5c4a7e3970b52f e0c546e
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
USD: renamed 'xform' to 'transform'

Sergey and I don't agree on 'tfm' vs. 'xform', so I just chose to not to
use either and avoid abbreviating altogether.

----------------------------------------
5 Paths Changed]]>
Wed, 11 Dec 2019 15:34:30 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/e0c546e45a821e8d353cd1841d5c4a7e3970b52fSybren A. Stüvel
<![CDATA[[542518d]: USD: Support '.usd' as export extension (thanks @superfunc)...]]> http://www.miikahweb.com/en/blender/git-logs/commit/542518d83ca73131187c1a7abdadbb296296d86a 542518d
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
USD: Support '.usd' as export extension (thanks @superfunc) and proper filtering in the file browser

----------------------------------------
5 Paths Changed]]>
Thu, 05 Dec 2019 17:32:22 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/542518d83ca73131187c1a7abdadbb296296d86aSybren A. Stüvel
<![CDATA[[649825b]: USD: Fixed export of animated meshes]]> http://www.miikahweb.com/en/blender/git-logs/commit/649825b91b9eac451763247cd3be1ab186ebdcc0 649825b
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
USD: Fixed export of animated meshes

I missed a bit earlier, when creating the mesh attributes with an explicit
default, causing meshes to be non-animated. Now I use the 'sparse value
writer', as recommended on the USD forum [1], and animated meshes are
properly written once again.

[1] https://groups.google.com/d/msg/usd-interest/cVJv_eDYxZo/oREDDm11AgAJ

----------------------------------------
3 Paths Changed]]>
Thu, 05 Dec 2019 17:32:26 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/649825b91b9eac451763247cd3be1ab186ebdcc0Sybren A. Stüvel
<![CDATA[[429d9ee]: USD: Allow running unit tests without 'make install' step]]> http://www.miikahweb.com/en/blender/git-logs/commit/429d9ee441f89e8082c434dad09e0f32d189863d 429d9ee
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
USD: Allow running unit tests without 'make install' step

When the PXR_PLUGINPATH_NAME environment variable is defined, the USD
library uses it to find its JSON files. This allows the unit tests to
run without having to 'make install' Blender.

----------------------------------------
1 Path Changed]]>
Fri, 29 Nov 2019 14:16:23 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/429d9ee441f89e8082c434dad09e0f32d189863dSybren A. Stüvel
<![CDATA[[3d41287]: USD: Fixed include path for unit tests, now TBB headers can...]]> http://www.miikahweb.com/en/blender/git-logs/commit/3d41287d86d76c8ad076234ef4cb7138853a7388 3d41287
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
USD: Fixed include path for unit tests, now TBB headers can be found

----------------------------------------
1 Path Changed]]>
Fri, 29 Nov 2019 13:42:34 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/3d41287d86d76c8ad076234ef4cb7138853a7388Sybren A. Stüvel
<![CDATA[[0cb5650]: USD: fixed paths in usd.diff]]> http://www.miikahweb.com/en/blender/git-logs/commit/0cb565047f60a946b90533ff6eec640b59169c33 0cb5650
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
USD: fixed paths in usd.diff

I made the previous diff with `git diff` in the USD source, which produced
paths incompatible with the patch command we use to apply it.

----------------------------------------
1 Path Changed]]>
Fri, 29 Nov 2019 11:27:45 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/0cb565047f60a946b90533ff6eec640b59169c33Sybren A. Stüvel
<![CDATA[[4f5c88b]: Cleanup: USD: remove unused header files]]> http://www.miikahweb.com/en/blender/git-logs/commit/4f5c88bde6cc0dac356a20151281f47151404bc9 4f5c88b
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
Cleanup: USD: remove unused header files

----------------------------------------
1 Path Changed]]>
Fri, 29 Nov 2019 10:18:29 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/4f5c88bde6cc0dac356a20151281f47151404bc9Sybren A. Stüvel
<![CDATA[[c455e55]: USD: Check location of USD JSON files in unit tests]]> http://www.miikahweb.com/en/blender/git-logs/commit/c455e55b5524fdc0e011f17ff2a1a726802453f1 c455e55
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
USD: Check location of USD JSON files in unit tests

This commit adds a test to see whether the USD JSON files can be found
and loaded. Simply the ability to create a USD Stage for a specific
filename means that the extension has been recognised by the USD
library, and that a USD plugin has been loaded to write such files.

USD has been patched to not only look in `{exe_directory}/lib/usd`, but
also in `{exe_directory}/../lib/usd`; the latter is required to resolve
the path for test executables in `bin/tests/`.

----------------------------------------
4 Paths Changed]]>
Fri, 29 Nov 2019 10:18:30 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/c455e55b5524fdc0e011f17ff2a1a726802453f1Sybren A. Stüvel
<![CDATA[[397447e]: USD: Windows-specific fixes by @LazyDodo]]> http://www.miikahweb.com/en/blender/git-logs/commit/397447e131a9e8964a7ea66666f1e0d8133dfdbd 397447e
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
USD: Windows-specific fixes by @LazyDodo

----------------------------------------
3 Paths Changed]]>
Thu, 28 Nov 2019 17:40:16 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/397447e131a9e8964a7ea66666f1e0d8133dfdbdSybren A. Stüvel
<![CDATA[[dc89540]: USD: removed more designated initializers]]> http://www.miikahweb.com/en/blender/git-logs/commit/dc89540be4b30f87ecd6b708650c5f2236a1d718 dc89540
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
USD: removed more designated initializers

----------------------------------------
1 Path Changed]]>
Thu, 28 Nov 2019 17:12:07 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/dc89540be4b30f87ecd6b708650c5f2236a1d718Sybren A. Stüvel
<![CDATA[[20ee2bd]: USD: Removed designated initializers as they are not supported...]]> http://www.miikahweb.com/en/blender/git-logs/commit/20ee2bd9dd06948524d5c78d16105067302a6980 20ee2bd
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
USD: Removed designated initializers as they are not supported in C++11

----------------------------------------
1 Path Changed]]>
Thu, 28 Nov 2019 17:01:06 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/20ee2bd9dd06948524d5c78d16105067302a6980Sybren A. Stüvel
<![CDATA[[0495842]: USD: build & install USD with 'make deps']]> http://www.miikahweb.com/en/blender/git-logs/commit/0495842ea540f7e4d8c00207e0e8ab0daad15c34 0495842
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
USD: build & install USD with 'make deps'

----------------------------------------
4 Paths Changed]]>
Thu, 28 Nov 2019 16:43:47 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/0495842ea540f7e4d8c00207e0e8ab0daad15c34Sybren A. Stüvel
<![CDATA[[08eee16]: USD: use BKE_object_visibility()]]> http://www.miikahweb.com/en/blender/git-logs/commit/08eee16d7fe6b090a1725a5ac7f2246d2fe9fa9f 08eee16
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
USD: use BKE_object_visibility()

----------------------------------------
1 Path Changed]]>
Thu, 28 Nov 2019 16:43:48 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/08eee16d7fe6b090a1725a5ac7f2246d2fe9fa9fSybren A. Stüvel
<![CDATA[[0fb7b64]: USD: Introducing USD support]]> http://www.miikahweb.com/en/blender/git-logs/commit/0fb7b64306837f75b0c3579d830ad0b8094b8b06 0fb7b64
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
USD: Introducing USD support

This commit introduces an exporter to Pixar's Universal Scene
Description (USD) format.

- The USD libraries are expected to be in /opt/usd/, not yet built by
install_deps.sh. I'll work on that while this patch is under review.
- Only experimental support for instancing; by default all duplicated
objects are made real in the USD file. This is fine for exporting a
linked-in posed character, not so much for thousands of pebbles etc.
- This patch contains LazyDodo's fixes for building on Windows in D5359.

== Meshes ==

USD seems to support neither per-material nor per-face-group
double-sidedness, so we just use the flag from the first non-empty
material slot. If there is no material we default to double-sidedness.

Each UV map is stored on the mesh in a separate primvar. Materials can
refer to these UV maps, but this is not yet exported by Blender. The
primvar name is the same as the UV Map name. This is to allow the
standard name "st" for texture coordinates by naming the UV Map as such,
without having to guess which UV Map is the "standard" one.

Face-varying mesh normals are written to USD. When the mesh has custom
loop normals those are written. Otherwise the poly flag `ME_SMOOTH` is
inspected to determine the normals.

The UV maps and mesh normals take up a significant amount of space, so
exporting them is optional. They're still enabled by default, though.
For comparison: a shot of Spring (03_035_A) is 1.2 GiB when exported
with UVs and normals, and 262 MiB without. We probably have room for
optimisation of written UVs and normals.

The mesh subdivision scheme isn't using the default value 'Catmull
Clark', but uses 'None', indicating we're exporting a polygonal mesh.
This is necessary for USD to understand our normals; otherwise the mesh
is always rendered smooth. In the future we may want to expose this
choice of subdivision scheme to the user, or auto-detect it when we
actually support exporting pre-subdivision meshes.

A possible optimisation could be to inspect whether all polygons are
smooth or flat, and mark the USD mesh as such. This can be added when
needed.

== Animation ==

Mesh and transform animation are now written when passing
`animation=True` to the export operator. There is no inspection of
whether an object is actually animated or not; USD can handle
deduplication of static values for us.

The administration of which timecode to use for the export is left to
the file-format-specific concrete subclasses of
`AbstractHierarchyIterator`; the abstract iterator itself doesn't know
anything about the passage of time. This will allow subclasses for the
frame-based USD format and time-based Alembic format.

== support for simple preview materials ==

Very simple versions of the materials are now exported, using only the
viewport diffuse RGB, metallic, and roughness.

When there are multiple materials, the mesh faces are stored as geometry
subset and each material is assigned to the appropriate subset. If there
is only one material this is skipped.

The first material if any) is always applied to the mesh itself
(regardless of the existence of geometry subsets), because the Hydra
viewport doesn't support materials on subsets. See
https://github.com/PixarAnimationStudios/USD/issues/542 for more info.

Note that the geometry subsets are not yet time-sampled, so it may break
when an animated mesh changes topology.

== Hair ==

Only the parent strands are exported, and only with a constant colour.
No UV coordinates, no information about the normals.

== Camera ==

Only perspective cameras are supported for now.

== Particles ==

Particles are only written when they are alive, which means that they
are always visible (there is currently no code that deals with marking
them as invisible outside their lifespan).

Particle-system-instanced objects are exported by suffixing the object
name with the particle's persistent ID, giving each particle XForm a
unique name.

== Instancing/referencing ==

This exporter has experimental support for instancing/referencing.

Dupli-object meshes are now written to USD as references to the original
mesh. This is still very limited in correctness, as there are issues
referencing to materials from a referenced mesh.

I am still committing this, as it gives us a place to start when
continuing the quest for proper instancing in USD.

== Lights ==

USD does not directly support spot lights, so those aren't exported yet.
It's possible to add this in the future via the UsdLuxShapingAPI. The
units used for the light intensity are also still a bit of a mystery.

== Fluid vertex velocities ==

Currently only fluid simulations (not meshes in general) have explicit
vertex velocities. This is the most important case for exporting
velocities, though, as the baked mesh changes topology all the time, and
thus computing the velocities at import time in a post-processing step
is hard.

----------------------------------------
34 Paths Changed]]>
Thu, 28 Nov 2019 16:43:47 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/0fb7b64306837f75b0c3579d830ad0b8094b8b06Sybren A. Stüvel
<![CDATA[[11c4344]: USD: renamed `should_export_object` to `mark_as_weak_export`]]> http://www.miikahweb.com/en/blender/git-logs/commit/11c434416bab692b4ed817de881621bbd881abbd 11c4344
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
USD: renamed `should_export_object` to `mark_as_weak_export`

The old name was confusing. The new name also matches the terminology
used in the HierarchyContext struct. I also added more comments to
clarify the intended functionality.

Note that this inverts the meaning of the returned value.

----------------------------------------
4 Paths Changed]]>
Thu, 28 Nov 2019 16:44:22 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/11c434416bab692b4ed817de881621bbd881abbdSybren A. Stüvel
<![CDATA[[1450ef6]: USD: Build improvements]]> http://www.miikahweb.com/en/blender/git-logs/commit/1450ef6c469088b4ca828eff592f1d67bc59e351 1450ef6
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
USD: Build improvements

- Removed the `USD_PATH` variable, expose `USD_ROOT_DIR` from `FindUSD.cmake`
instead.
- Properly call `find_package_wrapper(USD)` from `platform_unix.cmake`.
- Added USD files to `harvest.cmake`.
- Removed `external_python` from USD dependencies, as we don't use USD's
Python interface.
- Removed Fink and DarwinPorts support.
- Enable USD in `blender_full.cmake`

----------------------------------------
7 Paths Changed]]>
Thu, 28 Nov 2019 16:43:47 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/1450ef6c469088b4ca828eff592f1d67bc59e351Sybren A. Stüvel
<![CDATA[[25bfb5d]: Automated test for USD's AbstractHierarchyIterator]]> http://www.miikahweb.com/en/blender/git-logs/commit/25bfb5d44e8170fa87d45bea03c171d5ecfa13d7 25bfb5d
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
Automated test for USD's AbstractHierarchyIterator

----------------------------------------
3 Paths Changed]]>
Thu, 28 Nov 2019 16:43:47 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/25bfb5d44e8170fa87d45bea03c171d5ecfa13d7Sybren A. Stüvel
<![CDATA[[277bf3c]: USD: reuse `pxr::TfToken` objects]]> http://www.miikahweb.com/en/blender/git-logs/commit/277bf3c4e12b9203a6dc47012889ae3d8eb64ae3 277bf3c
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
USD: reuse `pxr::TfToken` objects

TfToken objects are not cheap to construct, so we do it once and reuse them.

----------------------------------------
1 Path Changed]]>
Thu, 28 Nov 2019 16:43:48 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/277bf3c4e12b9203a6dc47012889ae3d8eb64ae3Sybren A. Stüvel
<![CDATA[[298890c]: USD: add `_` suffix to non-public member variables]]> http://www.miikahweb.com/en/blender/git-logs/commit/298890c33becf40d4aaefd081443c868b6dc5c1e 298890c
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
USD: add `_` suffix to non-public member variables

----------------------------------------
3 Paths Changed]]>
Thu, 28 Nov 2019 16:43:48 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/298890c33becf40d4aaefd081443c868b6dc5c1eSybren A. Stüvel
<![CDATA[[3514405]: USD: Also `include pxrTargets-release.cmake` when harvesting...]]> http://www.miikahweb.com/en/blender/git-logs/commit/35144055a0179fcf89ec53e9d02258bac379c6cb 3514405
Branches : temp-sybren-usd-patch-02
Author : Sybren A. Stüvel (sybren)
----------------------------------------
USD: Also `include pxrTargets-release.cmake` when harvesting dependencies

----------------------------------------
1 Path Changed]]>
Thu, 28 Nov 2019 16:43:48 +0000 http://www.miikahweb.com/en/blender/git-logs/commit/35144055a0179fcf89ec53e9d02258bac379c6cbSybren A. Stüvel