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+
+**************************
+Blender as a Python Module
+**************************
+
+Blender supports being built as a Python module,
+allowing ``import bpy`` to be added to any Python script, providing access to Blender's features.
+
+.. note::
+
+ At time of writing official builds are not available,
+ using this requires compiling Blender yourself see
+ `build instructions <https://wiki.blender.org/w/index.php?title=Building_Blender/Other/BlenderAsPyModule>`__.
+
+
+Use Cases
+=========
+
+Python developers may wish to integrate Blender scripts which don't center around Blender.
+
+Possible uses include:
+
+- Visualizing data by rendering images and animations.
+- Image processing using Blender's compositor.
+- Video editing (using Blender's sequencer).
+- 3D file conversion.
+- Development, accessing ``bpy`` from Python IDE's and debugging tools for example.
+- Automation.
+
+
+Usage
+=====
+
+For the most part using Blender as a Python module is equivalent to running a script in background-mode
+(passing the command-line arguments ``--background`` or ``-b``),
+however there are some differences to be aware of.
+
+.. Sorted alphabetically as there isn't an especially a logical order to show them.
+
+Blender's Executable Access
+ The attribute :class:`bpy.app.binary_path` defaults to an empty string.
+
+ If you wish to point this to the location of a known executable you may set the value.
+
+ This example searches for the binary, setting it when found:
+
+ .. code-block:: python
+
+ import bpy
+ import shutil
+
+ blender_bin = shutil.which("blender")
+ if blender_bin:
+ print("Found:", blender_bin)
+ bpy.app.binary_path = blender_bin
+ else:
+ print("Unable to find blender!")
+
+Blender's Internal Modules
+ There are many modules included with Blender such as :mod:`gpu` and :mod:`mathuils`.
+ It's important that these are imported after ``bpy`` or they will not be found.
+
+Command Line Arguments Unsupported
+ Functionality controlled by command line arguments (shown by calling ``blender --help`` aren't accessible).
+
+ Typically this isn't such a limitation although there are some command line arguments that don't have
+ equivalents in Blender's Python API (``--threads`` and ``--log`` for example).
+
+ .. note::
+
+ Access to these settings may be added in the future as needed.
+
+Resource Sharing (GPU)
+ It's possible other Python modules make use of the GPU in a way that prevents Blender/Cycles from accessing the GPU.
+
+Signal Handlers
+ Blender's typical signal handlers are not initialized, so there is no special handling for ``Control-C``
+ to cancel a render and a crash log is not written in the event of a crash.
+
+Startup and Preferences
+ When the ``bpy`` module loads, the file is not empty as you might expect,
+ there is a default cube, camera and light. If you wish to start from a blank file use:
+ ``bpy.ops.wm.read_factory_settings(use_empty=True)``.
+
+ The users startup and preferences are ignored to prevent your local configuration from impacting scripts behavior.
+ The Python module behaves as if ``--factory-startup`` was passed as a command line argument.
+
+ The users preferences and startup can be loaded using operators:
+
+ .. code-block:: python
+
+ import bpy
+
+ bpy.ops.wm.read_userpref()
+ bpy.ops.wm.read_homefile()
+
+
+Limitations
+===========
+
+Most constraints of Blender as an application still apply:
+
+Reloading Unsupported
+ Reloading via ``importlib.reload`` will raise an exception instead of reloading and resetting the module.
+
+ The operator ``bpy.ops.wm.read_factory_settings()`` can be used to reset the internal state.
+
+Single Blend File Restriction
+ Only a single ``.blend`` file can be edited at a time.
+
+ .. hint::
+
+ As with the application it's possible to start multiple instances,
+ each with their own ``bpy`` and therefor Blender state.
+ Python provides the ``multiprocessing`` module to make communicating with sub-processes more convenient.
+
+ In some cases the library API may be an alternative to starting separate processes,
+ although this API operates on reading and writing ID data-blocks and isn't
+ a complete substitute for loading ``.blend`` files, see:
+
+ - :meth:`bpy.types.BlendDataLibraries.load`
+ - :meth:`bpy.types.BlendDataLibraries.write`
+ - :meth:`bpy.types.BlendData.temp_data`
+ supports a temporary data-context to avoid manipulating the current ``.blend`` file.