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Add 2 documents to the python api reference.

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- Blender/Python Addon Tutorial: a step by step guide on how to write an addon from scratch

- Blender/Python API Reference Usage: examples of how to use the API reference docs

Thanks to John Nyquist for editing these docs and giving feedback.
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Campbell Barton
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*******************
Reference API Usage
*******************
Blender has many interlinking data types which have an auto-generated reference api which often has the information
you need to write a script, but can be difficult to use.
This document is designed to help you understand how to use the reference api.
Reference API Scope
===================
The reference API covers :mod:`bpy.types`, which stores types accessed via :mod:`bpy.context` - *The user context*
or :mod:`bpy.data` - *Blend file data*.
Other modules such as :mod:`bge`, :mod:`bmesh` and :mod:`aud` are not using Blenders data API
so this document doesn't apply to those modules.
Data Access
===========
The most common case for using the reference API is to find out how to access data in the blend file.
Before going any further its best to be aware of ID Data-Blocks in Blender since you will often find properties
relative to them.
ID Data
-------
ID Data-Blocks are used in Blender as top-level data containers.
From the user interface this isn't so obvious, but when developing you need to know about ID Data-Blocks.
ID data types include Scene, Group, Object, Mesh, Screen, World, Armature, Image and Texture.
for a full list see the sub-classes of :class:`bpy.types.ID`
Here are some characteristics ID Data-Blocks share.
- ID's are blend file data, so loading a new blend file reloads an entire new set of Data-Blocks.
- ID's can be accessed in Python from ``bpy.data.*``
- Each data-block has a unique ``.name`` attribute, displayed in the interface.
- Animation data is stored in ID's ``.animation_data``.
- ID's are the only data types that can be linked between blend files.
- ID's can be added/copied and removed via Python.
- ID's have their own garbage-collection system which frees unused ID's when saving.
- When a data-block has a reference to some external data, this is typically an ID Data-Block.
Simple Data Access
------------------
Lets start with a simple case, say you wan't a python script to adjust the objects location.
Start by finding this setting in the interface ``Properties Window -> Object -> Transform -> Location``
From the button you can right click and select **Online Python Reference**, this will link you to:
:class:`bpy.types.Object.location`
Being an API reference, this link often gives little more information then the tool-tip, though some of the pages
include examples (normally at the top of the page).
At this point you may say *Now what?* - you know that you have to use ``.location`` and that its an array of 3 floats
but you're still left wondering how to access this in a script.
So the next step is to find out where to access objects, go down to the bottom of the page to the **References**
section, for objects there are many references, but one of the most common places to access objects is via the context.
It's easy to be overwhelmed at this point since there ``Object`` get referenced in so many places - modifiers,
functions, textures and constraints.
But if you want to access any data the user has selected
you typically only need to check the :mod:`bpy.context` references.
Even then, in this case there are quite a few though if you read over these - most are mode specific.
If you happen to be writing a tool that only runs in weight paint mode, then using ``weight_paint_object``
would be appropriate.
However to access an item the user last selected, look for the ``active`` members,
Having access to a single active member the user selects is a convention in Blender: eg. ``active_bone``,
``active_pose_bone``, ``active_node`` ... and in this case we can use - ``active_object``.
So now we have enough information to find the location of the active object.
.. code-block:: python
bpy.context.active_object.location
You can type this into the python console to see the result.
The other common place to access objects in the reference is :class:`bpy.types.BlendData.objects`.
.. note::
This is **not** listed as :mod:`bpy.data.objects`,
this is because :mod:`bpy.data` is an instance of the :class:`bpy.types.BlendData` class,
so the documentation points there.
With :mod:`bpy.data.objects`, this is a collection of objects so you need to access one of its members.
.. code-block:: python
bpy.data.objects["Cube"].location
Nested Properties
-----------------
The previous example is quite straightforward because ``location`` is a property of ``Object`` which can be accessed
from the context directly.
Here are some more complex examples:
.. code-block:: python
# access a render layers samples
bpy.context.scene.render.layers["RenderLayer"].samples
# access to the current weight paint brush size
bpy.context.tool_settings.weight_paint.brush.size
# check if the window is fullscreen
bpy.context.window.screen.show_fullscreen
As you can see there are times when you want to access data which is nested
in a way that causes you to go through a few indirections.
The properties are arranged to match how data is stored internally (in blenders C code) which is often logical but
not always quite what you would expect from using Blender.
So this takes some time to learn, it helps you understand how data fits together in Blender which is important
to know when writing scripts.
When starting out scripting you will often run into the problem where you're not sure how to access the data you want.
There are a few ways to do this.
- Use the Python console's auto-complete to inspect properties. *This can be hit-and-miss but has the advantage
that you can easily see the values of properties and assign them to interactively see the results.*
- Copy the Data-Path from the user interface. *Explained further in :ref:`Copy Data Path <info_data_path_copy>`*
- Using the documentation to follow references. *Explained further in :ref:`Indirect Data Access <info_data_path_indirect>`*
.. _info_data_path_copy
Copy Data Path
--------------
Blender can compute the Python string to a property which is shown in the tool-tip, on the line below ``Python: ...``,
This saves having to use the API reference to click back up the references to find where data is accessed from.
There is a user-interface feature to copy the data-path which gives the path from an :class:`bpy.types.ID` data-block,
to its property.
To see how this works we'll get the path to the Subdivision-Surface modifiers subdivision setting.
Start with the default scene and select the **Modifiers** tab, then add a **Subdivision-Surface** modifier to the cube.
Now hover your mouse over the button labeled **View**, The tool-tip includes :class:`bpy.types.SubsurfModifier.levels`
but we want the path from the object to this property.
Note that the text copied won't include the ``bpy.data.collection["name"].`` component since its assumed that
you won't be doing collection look-ups on every access and typically you'll want to use the context rather
then access each :class:`bpy.types.ID` instance by name.
Type in the ID path into a Python console :mod:`bpy.context.active_object`. Include the trailing dot and don't hit "enter", yet.
Now right-click on the button and select **Copy Data Path**, then paste the result into the console.
So now you should have the answer:
.. code-block:: python
bpy.context.active_object.modifiers["Subsurf"].levels
Hit "enter" and you'll get the current value of 1. Now try changing the value to 2:
.. code-block:: python
bpy.context.active_object.modifiers["Subsurf"].levels = 2
You can see the value update in the Subdivision-Surface modifier's UI as well as the cube.
.. _info_data_path_indirect
Indirect Data Access
--------------------
For this example we'll go over something more involved, showing the steps to access the active sculpt brushes texture.
Lets say we want to access the texture of a brush via Python, to adjust its ``contrast`` for example.
- Start in the default scene and enable 'Sculpt' mode from the 3D-View header.
- From the toolbar expand the **Texture** panel and add a new texture.
*Notice the texture button its self doesn't have very useful links (you can check the tool-tips).*
- The contrast setting isn't exposed in the sculpt toolbar, so view the texture in the properties panel...
- In the properties button select the Texture context.
- Select the Brush icon to show the brush texture.
- Expand the **Colors** panel to locate the **Contrast** button.
- Right click on the contrast button and select **Online Python Reference** This takes you to ``bpy.types.Texture.contrast``
- Now we can see that ``contrast`` is a property of texture, so next we'll check on how to access the texture from the brush.
- Check on the **References** at the bottom of the page, sometimes there are many references, and it may take
some guess work to find the right one, but in this case its obviously ``Brush.texture``.
*Now we know that the texture can be accessed from* ``bpy.data.brushes["BrushName"].texture``
*but normally you won't want to access the brush by name, so we'll see now to access the active brush instead.*
- So the next step is to check on where brushes are accessed from via the **References**.
In this case there is simply ``bpy.context.brush`` which is all we need.
Now you can use the Python console to form the nested properties needed to access brush textures contrast,
logically we now know.
*Context -> Brush -> Texture -> Contrast*
Since the attribute for each is given along the way we can compose the data path in the python console:
.. code-block:: python
bpy.context.brush.texture.contrast
There can be multiple ways to access the same data, which you choose often depends on the task.
An alternate path to access the same setting is...
.. code-block:: python
bpy.context.sculpt.brush.texture.contrast
Or access the brush directly...
.. code-block:: python
bpy.data.brushes["BrushName"].texture.contrast
If you are writing a user tool normally you want to use the :mod:`bpy.context` since the user normally expects
the tool to operate on what they have selected.
For automation you are more likely to use :mod:`bpy.data` since you want to be able to access specific data and manipulate
it, no matter what the user currently has the view set at.
Operators
=========
Most key-strokes and buttons in Blender call an operator which is also exposed to python via :mod:`bpy.ops`,
To see the Python equivalent hover your mouse over the button and see the tool-tip,
eg ``Python: bpy.ops.render.render()``,
If there is no tool-tip or the ``Python:`` line is missing then this button is not using an operator and
can't be accessed from Python.
If you want to use this in a script you can press :kbd:`Control-C` while your mouse is over the button to copy it to the
clipboard.
You can also right click on the button and view the **Online Python Reference**, this mainly shows arguments and
their defaults however operators written in Python show their file and line number which may be useful if you
are interested to check on the source code.
.. note::
Not all operators can be called usefully from Python, for more on this see :ref:`using operators <using_operators>`.
Info View
---------
Blender records operators you run and displays them in the **Info** space.
This is located above the file-menu which can be dragged down to display its contents.
Select the **Script** screen that comes default with Blender to see its output.
You can perform some actions and see them show up - delete a vertex for example.
Each entry can be selected (Right-Mouse-Button), then copied :kbd:`Control-C`, usually to paste in the text editor or python console.
.. note::
Not all operators get registered for display,
zooming the view for example isn't so useful to repeat so its excluded from the output.
To display *every* operator that runs see :ref:`Show All Operators <info_show_all_operators>`

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This document attempts to help you work with the Blender API in areas that can be troublesome and avoid practices that are known to give instability.
.. _using_operators:
Using Operators
===============

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.. _info_overview:
*******************
Python API Overview
*******************

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.. _info_quickstart:
***********************
Quickstart Introduction
***********************

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.. note::
This uses the same method for creating the animation path used by :class:`FCurve.data_path` and :class:`DriverTarget.data_path` drivers.
This uses the same method for creating the animation path used by :class:`bpy.types.FCurve.data_path` and :class:`bpy.types.DriverTarget.data_path` drivers.
.. _info_show_all_operators
Show All Operators
==================
While blender logs operators in the Info space, this only reports operators with the ``REGISTER`` option enabeld so as not to flood the Info view with calls to ``bpy.ops.view3d.smoothview`` and ``bpy.ops.view3d.zoom``.
However, for testing it can be useful to see **every** operator called in a terminal, do this by enabling the debug option either by passing the ``--debug`` argument when starting blender or by setting :mod:`bpy.app.debug` to True while blender is running.
However, for testing it can be useful to see **every** operator called in a terminal, do this by enabling the debug option either by passing the ``--debug-wm`` argument when starting blender or by setting :mod:`bpy.app.debug_wm` to True while blender is running.
Use an External Editor

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Addon Tutorial
##############
************
Introduction
************
Intended Audience
=================
This tutorial is designed to help technical artists or developers learn to extend Blender.
An understanding of the basics of Python is expected for those working through this tutorial.
Prerequisites
-------------
Before going through the tutorial you should...
* Familiarity with the basics of working in Blender.
* Know how to run a script in Blender's text editor (as documented in the quick-start)
* Have an understanding of Python primitive types (int, boolean, string, list, tuple, dictionary, and set).
* Be familiar with the concept of Python modules.
* Basic understanding of classes (object orientation) in Python.
Suggested reading before starting this tutorial.
* `Dive Into Python <http://getpython3.com/diveintopython3/index.html>`_ sections (1, 2, 3, 4, and 7).
* :ref:`Blender API Quickstart <info_quickstart>`
to help become familiar with Blender/Python basics.
To best troubleshoot any error message Python prints while writing scripts you run blender with from a terminal,
see :ref:`Use The Terminal <use_the_terminal>`.
Documentation Links
===================
While going through the tutorial you may want to look into our reference documentation.
* :ref:`Blender API Overview <info_overview>`. -
*This document is rather detailed but helpful if you want to know more on a topic.*
* :mod:`bpy.context` api reference. -
*Handy to have a list of available items your script may operate on.*
* :class:`bpy.types.Operator`. -
*The following addons define operators, these docs give details and more examples of operators.*
******
Addons
******
What is an Addon?
=================
An addon is simply a Python module with some additional requirements so Blender can display it in a list with useful
information.
To give an example, here is the simplest possible addon.
.. code-block:: python
bl_info = {"name": "My Test Addon", "category": "Object"}
def register():
print("Hello World")
def unregister():
print("Goodbye World")
* ``bl_info`` is a dictionary containing addon meta-data such as the title, version and author to be displayed in the
user preferences addon list.
* ``register`` is a function which only runs when enabling the addon, this means the module can be loaded without
activating the addon.
* ``unregister`` is a function to unload anything setup by ``register``, this is called when the addon is disabled.
Notice this addon does not do anything related to Blender, (the :mod:`bpy` module is not imported for example).
This is a contrived example of an addon that serves to illustrate the point
that the base requirements of an addon are simple.
An addon will typically register operators, panels, menu items etc, but its worth noting that _any_ script can do this,
when executed from the text editor or even the interactive console - there is nothing inherently different about an
addon that allows it to integrate with Blender, such functionality is just provided by the :mod:`bpy` module for any
script to access.
So an addon is just a way to encapsulate a Python module in a way a user can easily utilize.
.. note::
Running this script within the text editor won't print anything,
to see the output it must be installed through the user preferences.
Messages will be printed when enabling and disabling.
Your First Addon
================
The simplest possible addon above was useful as an example but not much else.
This next addon is simple but shows how to integrate a script into Blender using an ``Operator``
which is the typical way to define a tool accessed from menus, buttons and keyboard shortcuts.
For the first example we'll make a script that simply moves all objects in a scene.
Write The Script
----------------
Add the following script to the text editor in Blender.
.. code-block:: python
import bpy
scene = bpy.context.scene
for obj in scene.objects:
obj.location.x += 1.0
.. image:: run_script.png
:width: 924px
:align: center
:height: 574px
:alt: Run Script button
Click the Run Script button, all objects in the active scene are moved by 1.0 Blender unit.
Next we'll make this script into an addon.
Write the Addon (Simple)
------------------------
This addon takes the body of the script above, and adds them to an operator's ``execute()`` function.
.. code-block:: python
bl_info = {
"name": "Move X Axis",
"category": "Object",
}
import bpy
class ObjectMoveX(bpy.types.Operator):
"""My Object Moving Script""" # blender will use this as a tooltip for menu items and buttons.
bl_idname = "object.move_x" # unique identifier for buttons and menu items to reference.
bl_label = "Move X by One" # display name in the interface.
bl_options = {'REGISTER', 'UNDO'} # enable undo for the operator.
def execute(self, context): # execute() is called by blender when running the operator.
# The original script
scene = context.scene
for obj in scene.objects:
obj.location.x += 1.0
return {'FINISHED'} # this lets blender know the operator finished successfully.
def register():
bpy.utils.register_class(ObjectMoveX)
def unregister():
bpy.utils.unregister_class(ObjectMoveX)
# This allows you to run the script directly from blenders text editor
# to test the addon without having to install it.
if __name__ == "__main__":
register()
.. note:: ``bl_info`` is split across multiple lines, this is just a style convention used to more easily add items.
.. note:: Rather than using ``bpy.context.scene``, we use the ``context.scene`` argument passed to ``execute()``.
In most cases these will be the same however in some cases operators will be passed a custom context
so script authors should prefer the ``context`` argument passed to operators.
To test the script you can copy and paste this into Blender text editor and run it, this will execute the script
directly and call register immediately.
However running the script wont move any objects, for this you need to execute the newly registered operator.
.. image:: spacebar.png
:width: 924px
:align: center
:height: 574px
:alt: Spacebar
Do this by pressing ``SpaceBar`` to bring up the operator search dialog and type in "Move X by One" (the ``bl_label``),
then press ``Enter``.
The objects should move as before.
*Keep this addon open in Blender for the next step - Installing.*
Install The Addon
-----------------
Once you have your addon within in Blender's text editor, you will want to be able to install it so it can be enabled in
the user preferences to load on startup.
Even though the addon above is a test, lets go through the steps anyway so you know how to do it for later.
To install the Blender text as an addon you will first have to save it to disk, take care to obey the naming
restrictions that apply to Python modules and end with a ``.py`` extension.
Once the file is on disk, you can install it as you would for an addon downloaded online.
Open the user **File -> User Preferences**, Select the **Addon** section, press **Install Addon...** and select the file.
Now the addon will be listed and you can enable it by pressing the check-box, if you want it to be enabled on restart,
press **Save as Default**.
.. note::
The destination of the addon depends on your Blender configuration.
When installing an addon the source and destination path are printed in the console.
You can also find addon path locations by running this in the Python console.
.. code-block:: python
import addon_utils
print(addon_utils.paths())
More is written on this topic here:
`Directory Layout <http://wiki.blender.org/index.php/Doc:2.6/Manual/Introduction/Installing_Blender/DirectoryLayout>`_
Your Second Addon
=================
For our second addon, we will focus on object instancing - this is - to make linked copies of an object in a
similar way to what you may have seen with the array modifier.
Write The Script
----------------
As before, first we will start with a script, develop it, then convert into an addon.
.. code-block:: python
import bpy
from bpy import context
# Get the current scene
scene = context.scene
# Get the 3D cursor
cursor = scene.cursor_location
# Get the active object (assume we have one)
obj = scene.objects.active
# Now make a copy of the object
obj_new = obj.copy()
# The object won't automatically get into a new scene
scene.objects.link(obj_new)
# Now we can place the object
obj_new.location = cursor
Now try copy this script into Blender and run it on the default cube.
Make sure you click to move the 3D cursor before running as the duplicate will appear at the cursor's location.
... go off and test ...
After running, notice that when you go into edit-mode to change the cube - all of the copies change,
in Blender this is known as *Linked-Duplicates*.
Next, we're going to do this in a loop, to make an array of objects between the active object and the cursor.
.. code-block:: python
import bpy
from bpy import context
scene = context.scene
cursor = scene.cursor_location
obj = scene.objects.active
# Use a fixed value for now, eventually make this user adjustable
total = 10
# Add 'total' objects into the scene
for i in range(total):
obj_new = obj.copy()
scene.objects.link(obj_new)
# Now place the object in between the cursor
# and the active object based on 'i'
factor = i / total
obj_new.location = (obj.location * factor) + (cursor * (1.0 - factor))
Try run this script with with the active object and the cursor spaced apart to see the result.
With this script you'll notice we're doing some math with the object location and cursor, this works because both are
3D :class:`mathutils.Vector` instances, a convenient class provided by the :mod:`mathutils` module and
allows vectors to be multiplied by numbers and matrices.
If you are interested in this area, read into :class:`mathutils.Vector` - there are many handy utility functions
such as getting the angle between vectors, cross product, dot products
as well as more advanced functions in :mod:`mathutils.geometry` such as bezier spline interpolation and
ray-triangle intersection.
For now we'll focus on making this script an addon, but its good to know that this 3D math module is available and
can help you with more advanced functionality later on.
Write the Addon
---------------
The first step is to convert the script as-is into an addon.
.. code-block:: python
bl_info = {
"name": "Cursor Array",
"category": "Object",
}
import bpy
class ObjectCursorArray(bpy.types.Operator):
"""Object Cursor Array"""
bl_idname = "object.cursor_array"
bl_label = "Cursor Array"
bl_options = {'REGISTER', 'UNDO'}
def execute(self, context):
scene = context.scene
cursor = scene.cursor_location
obj = scene.objects.active
total = 10
for i in range(total):
obj_new = obj.copy()
scene.objects.link(obj_new)
factor = i / total
obj_new.location = (obj.location * factor) + (cursor * (1.0 - factor))
return {'FINISHED'}
def register():
bpy.utils.register_class(ObjectCursorArray)
def unregister():
bpy.utils.unregister_class(ObjectCursorArray)
if __name__ == "__main__":
register()
Everything here has been covered in the previous steps, you may want to try run the addon still
and consider what could be done to make it more useful.
... go off and test ...
The two of the most obvious missing things are - having the total fixed at 10, and having to access the operator from
space-bar is not very convenient.
Both these additions are explained next, with the final script afterwards.
Operator Property
^^^^^^^^^^^^^^^^^
There are a variety of property types that are used for tool settings, common property types include:
int, float, vector, color, boolean and string.
These properties are handled differently to typical Python class attributes
because Blender needs to be display them in the interface,
store their settings in key-maps and keep settings for re-use.
While this is handled in a fairly Pythonic way, be mindful that you are in fact defining tool settings that
are loaded into Blender and accessed by other parts of Blender, outside of Python.
To get rid of the literal 10 for `total`, we'll us an operator property.
Operator properties are defined via bpy.props module, this is added to the class body.
.. code-block:: python
# moved assignment from execute() to the body of the class...
total = bpy.props.IntProperty(name="Steps", default=2, min=1, max=100)
# and this is accessed on the class
# instance within the execute() function as...
self.total
These properties from :mod:`bpy.props` are handled specially by Blender when the class is registered
so they display as buttons in the user interface.
There are many arguments you can pass to properties to set limits, change the default and display a tooltip.
.. seealso:: :mod:`bpy.props.IntProperty`
This document doesn't go into details about using other property types,
however the link above includes examples of more advanced property usage.
Menu Item
^^^^^^^^^
Addons can add to the user interface of existing panels, headers and menus defined in Python.
For this example we'll add to an existing menu.
.. image:: menu_id.png
:width: 334px
:align: center
:height: 128px
:alt: Menu Identifier
To find the identifier of a menu you can hover your mouse over the menu item and the identifier is displayed.
The method used for adding a menu item is to append a draw function into an existing class.
.. code-block:: python
def menu_func(self, context):
self.layout.operator(ObjectCursorArray.bl_idname)
def register():
bpy.types.VIEW3D_MT_object.append(menu_func)
For docs on extending menus see: :doc:`bpy.types.Menu`.
Keymap
^^^^^^
In Blender addons have their own key-maps so as not to interfere with Blenders built in key-maps.
In the example below, a new object-mode :class:`bpy.types.KeyMap` is added,
then a :class:`bpy.types.KeyMapItem` is added to the key-map which references our newly added operator,
using :kbd:`Ctrl-Shift-Space` as the key shortcut to activate it.
.. code-block:: python
# store keymaps here to access after registration
addon_keymaps = []
def register():
# handle the keymap
wm = bpy.context.window_manager
km = wm.keyconfigs.addon.keymaps.new(name='Object Mode', space_type='EMPTY')
kmi = km.keymap_items.new(ObjectCursorArray.bl_idname, 'SPACE', 'PRESS', ctrl=True, shift=True)
kmi.properties.total = 4
addon_keymaps.append(km)
def unregister():
# handle the keymap
wm = bpy.context.window_manager
for km in addon_keymaps:
wm.keyconfigs.addon.keymaps.remove(km)
# clear the list
addon_keymaps.clear()
Notice how the key-map item can have a different ``total`` setting then the default set by the operator,
this allows you to have multiple keys accessing the same operator with different settings.
.. note::
While :kbd:`Ctrl-Shift-Space` isn't a default Blender key shortcut, its hard to make sure addons won't
overwrite each others keymaps, At least take care when assigning keys that they don't
conflict with important functionality within Blender.
For API documentation on the functions listed above, see:
:class:`bpy.types.KeyMaps.new`,
:class:`bpy.types.KeyMap`,
:class:`bpy.types.KeyMapItems.new`,
:class:`bpy.types.KeyMapItem`.
Bringing it all together
^^^^^^^^^^^^^^^^^^^^^^^^
.. code-block:: python
bl_info = {
"name": "Cursor Array",
"category": "Object",
}
import bpy
class ObjectCursorArray(bpy.types.Operator):
"""Object Cursor Array"""
bl_idname = "object.cursor_array"
bl_label = "Cursor Array"
bl_options = {'REGISTER', 'UNDO'}
total = bpy.props.IntProperty(name="Steps", default=2, min=1, max=100)
def execute(self, context):
scene = context.scene
cursor = scene.cursor_location
obj = scene.objects.active
for i in range(self.total):
obj_new = obj.copy()
scene.objects.link(obj_new)
factor = i / self.total
obj_new.location = (obj.location * factor) + (cursor * (1.0 - factor))
return {'FINISHED'}
def menu_func(self, context):
self.layout.operator(ObjectCursorArray.bl_idname)
# store keymaps here to access after registration
addon_keymaps = []
def register():
bpy.utils.register_class(ObjectCursorArray)
bpy.types.VIEW3D_MT_object.append(menu_func)
# handle the keymap
wm = bpy.context.window_manager
km = wm.keyconfigs.addon.keymaps.new(name='Object Mode', space_type='EMPTY')
kmi = km.keymap_items.new(ObjectCursorArray.bl_idname, 'SPACE', 'PRESS', ctrl=True, shift=True)
kmi.properties.total = 4
addon_keymaps.append(km)
def unregister():
bpy.utils.unregister_class(ObjectCursorArray)
bpy.types.VIEW3D_MT_object.remove(menu_func)
# handle the keymap
wm = bpy.context.window_manager
for km in addon_keymaps:
wm.keyconfigs.addon.keymaps.remove(km)
# clear the list
del addon_keymaps[:]
if __name__ == "__main__":
register()
.. image:: in_menu.png
:width: 591px
:align: center
:height: 649px
:alt: In the menu
Run the script (or save it and add it through the Preferences like before) and it will appear in the menu.
.. image:: op_prop.png
:width: 669px
:align: center
:height: 644px
:alt: Operator Property
After selecting it from the menu, you can choose how many instance of the cube you want created.
.. note::
Directly executing the script multiple times will add the menu each time too.
While not useful behavior, theres nothing to worry about since addons won't register them selves multiple
times when enabled through the user preferences.
Conclusions
===========
Addons can encapsulate certain functionality neatly for writing tools to improve your work-flow or for writing utilities
for others to use.
While there are limits to what Python can do within Blender, there is certainly a lot that can be achieved without
having to dive into Blender's C/C++ code.
The example given in the tutorial is limited, but shows the Blender API used for common tasks that you can expand on
to write your own tools.
Further Reading
---------------
Blender comes commented templates which are accessible from the text editor header, if you have specific areas
you want to see example code for, this is a good place to start.
Here are some sites you might like to check on after completing this tutorial.
* :ref:`Blender/Python API Overview <info_overview>` -
*For more background details on Blender/Python integration.*
* `How to Think Like a Computer Scientist <http://interactivepython.org/courselib/static/thinkcspy/index.html>`_ -
*Great info for those who are still learning Python.*
* `Blender Development (Wiki) <http://wiki.blender.org/index.php/Dev:Contents>`_ -
*Blender Development, general information and helpful links.*
* `Blender Artists (Coding Section) <http://blenderartists.org/forum/forumdisplay.php?47-Coding>`_ -
*forum where people ask Python development questions*

7
doc/python_api/sphinx_doc_gen.py
View File

@@ -316,6 +316,8 @@ RST_DIR = os.path.abspath(os.path.join(SCRIPT_DIR, "rst"))
INFO_DOCS = (
("info_quickstart.rst", "Blender/Python Quickstart: new to blender/scripting and want to get your feet wet?"),
("info_overview.rst", "Blender/Python API Overview: a more complete explanation of python integration"),
("info_tutorial_addon.rst", "Blender/Python Addon Tutorial: a step by step guide on how to write an addon from scratch"),
("info_api_reference.rst", "Blender/Python API Reference Usage: examples of how to use the API reference docs"),
("info_best_practice.rst", "Best Practice: Conventions to follow for writing good scripts"),
("info_tips_and_tricks.rst", "Tips and Tricks: Hints to help you while writing scripts for blender"),
("info_gotcha.rst", "Gotcha's: some of the problems you may come up against when writing scripts"),
@@ -1724,6 +1726,11 @@ def copy_handwritten_rsts(basepath):
# changelog
shutil.copy2(os.path.join(RST_DIR, "change_log.rst"), basepath)
# copy images, could be smarter but just glob for now.
for f in os.listdir(RST_DIR):
if f.endswith(".png"):
shutil.copy2(os.path.join(RST_DIR, f), basepath)
def rna2sphinx(basepath):