move blender stuff

Author: tomvanmele

docs/gettingstarted/blender.rst

@@ -189,3 +189,85 @@ After that starting Blender from the command line is much simpler.
 .. code-block:: bash
 
     blender
+
+Scripting Interface
+===================
+
+To switch to the scripting interface, simply select the "Scripting" tab of the main window.
+
+The scripting interface has an embedded interactive Python terminal, which is located in the bottom half of the main window on the left.
+If COMPAS was successfully installed you can use it to directly access the ``conda`` environment from where the installation was executed.
+
+.. code-block:: python
+
+    >>> import compas
+    >>> import compas_blender
+    >>> import numpy
+    >>> import scipy
+    >>> import bpy
+
+The script editor is quite simple but good enough for basic development.
+Line numbers and syntax highlighting should be on by default, but if that is not the case,
+they can be turned on with toggle buttons at the top right of the area.
+Further customisation of the editor appearance is possible by opening the sidebar from the "View" menu of the editor.
+
+Basic Usage
+===========
+
+One of the main advantages of working in Blender is that Blender Python is CPython, and not IronPython like in Rhino and Grasshopper.
+This means that all cool Python libraries are directly available and do not need to be accessed through remote procedure calls (RPC).
+Especially for code that relies heavily on libraries such as Numpy and Scipy this simplifies the development process quite significantly.
+
+.. code-block:: python
+
+    import compas
+    import compas_blender
+    from compas.datastructures import Mesh
+    from compas_blender.artists import MeshArtist
+
+    compas_blender.clear()
+
+    mesh = Mesh.from_ply(compas.get('bunny.ply'))
+
+    artist = MeshArtist(mesh)
+    artist.draw_mesh()
+
+
+Data Blocks
+-----------
+
+Something worth explaining is the use of ``compas_blender.clear()`` in this script.
+Blender uses (and re-uses) something called "data blocks".
+Objects in the scene have instances of these data blocks assigned to them.
+Multiple objects can be linked to the same data block.
+As a result, simply deleting an object from the scene will delete the object but not the underlying data block.
+
+If you run a script multiple times,
+even if you delete the scene objects between consecutive runs,
+you will accumulate the data blocks from previous runs and after a while Blender will become very slow.
+
+``compas_blender.clear()`` attempts to clean up not only the scene objects but also the data blocks.
+If somehow you still experience a slowdown, restarting Blender will help (all unused data blocks are then automatically removed).
+
+
+Layers
+------
+
+There are no real layers in Blender; at least not like the layers in, for example, Rhino.
+Therefore, the Blender artists have no optional ``layer`` parameter and no ``clear_layer`` method.
+Instead, objects are grouped in collections, which can be turned on and off in the Blender UI similar to layers in Rhino.
+
+
+Collections
+-----------
+
+
+Limitations
+===========
+
+``compas_blender`` is not yet as well developed as, ``compas_rhino`` and ``compas_ghpython``.
+For example, COMPAS geometry objects do not yet have a corresponding artist in ``compas_blender``.
+Artists are currently only available for data structures and robots.
+
+There is also no official system yet for making custom COMPAS tools in Blender.
+Therefore, COMPAS Blender development is somewhat limited to individual scripts.