build draco lib when building blender as a python module #125556

BuildXYZ · 2024-07-28T05:53:16+02:00

BuildXYZ commented

2024-07-28 05:53:16 +02:00

Problem:
Building Blender as a Python module does not support Draco compression when exporting using gltf. This is important for my application but has also been brought up on forums and as issue 113469

Solution:
Blender cmake files will need to be updated to lift restrictions on building the external Draco library when also setting WITH_PYTHON_MODULE=ON. Changes made should not impact other targets and install has been updated for all platforms.

With these changes it is now it is possible to do:

cmake -C ../blender/build_files/cmake/config/bpy_module.cmake ../blender -DWITH_DRACO=ON

The result after make install is that libextern_draco.dylib will now be present in [build_dir]/bin/bpy/lib

glTF-Blender-IO will need to perform an additional search for Draco library in the usual Python module location. Note users can set BLENDER_EXTERN_DRACO_LIBRARY_PATH but this additional search streamlines the usage of Draco compression when using Python as a module. The proposed search uses an extension wildcard so it should word cross-platorm. PR for glTF-Blender-IO submitted here: https://github.com/KhronosGroup/glTF-Blender-IO/pull/2300

Test confirming Draco compression is enable if libextern_draco.dylib is present in [bpy_dir]/lib:

bpy.ops.export_scene.gltf(
    filepath=os.path.join('/tmp', 'draco_test.glb'),
    export_format='GLB',
    export_apply=True,
    use_visible=True,
    export_draco_mesh_compression_enable=True
)

gltf-transform inspect /tmp/draco_test.glb

 OVERVIEW
 ────────────────────────────────────────────
┌────────────────────┬───────────────────────────────────────────────────┐
│ key                │ value                                             │
├────────────────────┼───────────────────────────────────────────────────┤
│ version            │ 2.0                                               │
├────────────────────┼───────────────────────────────────────────────────┤
│ generator          │ Khronos glTF Blender I/O v4.2.57                  │
├────────────────────┼───────────────────────────────────────────────────┤
│ extensionsUsed     │ KHR_draco_mesh_compression, KHR_texture_transform │
├────────────────────┼───────────────────────────────────────────────────┤
│ extensionsRequired │ KHR_draco_mesh_compression, KHR_texture_transform │
└────────────────────┴───────────────────────────────────────────────────┘

**Problem:** Building Blender as a Python module does not support Draco compression when exporting using gltf. This is important for my application but has also been brought up on forums and as issue [113469](https://projects.blender.org/blender/blender/issues/113469) **Solution:** Blender cmake files will need to be updated to lift restrictions on building the external Draco library when also setting `WITH_PYTHON_MODULE=ON`. Changes made should not impact other targets and `install` has been updated for all platforms. With these changes it is now it is possible to do: ```bash cmake -C ../blender/build_files/cmake/config/bpy_module.cmake ../blender -DWITH_DRACO=ON ``` The result after `make install` is that `libextern_draco.dylib` will now be present in `[build_dir]/bin/bpy/lib` [glTF-Blender-IO](https://github.com/KhronosGroup/glTF-Blender-IO) will need to perform an additional search for Draco library in the usual Python module location. Note users can set `BLENDER_EXTERN_DRACO_LIBRARY_PATH` but this additional search streamlines the usage of Draco compression when using Python as a module. The proposed search uses an extension wildcard so it should word cross-platorm. PR for glTF-Blender-IO submitted here: https://github.com/KhronosGroup/glTF-Blender-IO/pull/2300 Test confirming Draco compression is enable if `libextern_draco.dylib` is present in `[bpy_dir]/lib`: ```python bpy.ops.export_scene.gltf( filepath=os.path.join('/tmp', 'draco_test.glb'), export_format='GLB', export_apply=True, use_visible=True, export_draco_mesh_compression_enable=True ) ``` ```bash gltf-transform inspect /tmp/draco_test.glb OVERVIEW ──────────────────────────────────────────── ┌────────────────────┬───────────────────────────────────────────────────┐ │ key │ value │ ├────────────────────┼───────────────────────────────────────────────────┤ │ version │ 2.0 │ ├────────────────────┼───────────────────────────────────────────────────┤ │ generator │ Khronos glTF Blender I/O v4.2.57 │ ├────────────────────┼───────────────────────────────────────────────────┤ │ extensionsUsed │ KHR_draco_mesh_compression, KHR_texture_transform │ ├────────────────────┼───────────────────────────────────────────────────┤ │ extensionsRequired │ KHR_draco_mesh_compression, KHR_texture_transform │ └────────────────────┴───────────────────────────────────────────────────┘ ``` ```

BuildXYZ added 1 commit 2024-07-28 05:53:29 +02:00

build draco lib when building blender as a python module

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67355fe07d

Iliya Katushenock added this to the Platforms, Builds Tests & Devices project 2024-07-29 12:11:22 +02:00

BuildXYZ referenced this pull request

2024-07-31 01:15:19 +02:00

Python Module can't find Draco library #113469

Julien Duroure commented

2024-08-19 16:51:37 +02:00

Hello @LazyDodo and @ideasman42

This PR add builing Draco for bpy as a module (this is not the case for now in main)
Can you please review it?

Hello @LazyDodo and @ideasman42 This PR add builing Draco for bpy as a module (this is not the case for now in main) Can you please review it?

Julien Duroure requested review from Ray molenkamp 2024-08-19 16:52:12 +02:00

Julien Duroure requested review from Campbell Barton 2024-08-19 16:52:23 +02:00

Campbell Barton approved these changes 2024-08-20 06:51:46 +02:00

Ray molenkamp commented

2024-08-28 14:30:32 +02:00

@blender-bot package bpy

Blender Bot commented

2024-08-28 14:30:34 +02:00

Unknown platform bpy. See documentation for details.

Unknown platform `bpy`. See [documentation](https://projects.blender.org/infrastructure/blender-bot/src/branch/main/README.md) for details.

Julien Duroure commented

2024-09-05 15:13:50 +02:00

@LazyDodo Any news on that?
Seems the buildbot failed.
Is that link to the PR or something is wrong with configuration for package bpy?

@LazyDodo Any news on that? Seems the buildbot failed. Is that link to the PR or something is wrong with configuration for package bpy?

Ray molenkamp commented

2024-09-05 16:10:24 +02:00

No news, i just prodded the linux maintainer to look at the linux failure, and we'll likely need devops for the windows one, but they are unavailable till atleast the 15th, so it could be a bit