First Steps
===========

This example covers your first steps with the Guerilla python sdk.

Selection
---------

To start, let's select something in our scene

.. code-block:: python

   from guerilla import Modifier, pynode
   with Modifier() as mod:
       # select RenderGraph node 
       # replace current selection
       mod.select(['RenderGraph'], mode='replace')

Access Nodes
------------

Access nodes of the scene with their path

.. code-block:: python

    from guerilla import pynode
    # Look up the Output inside the RenderGraph
    n = pynode ('RenderGraph|Output')
    # You can also use the _ function, which is equivalent
    from guerilla import _
    n = _('RenderGraph|Output')
    # Both the pynode and _ functions are equivalent to:
    from guerilla import Document
    n = Document ().findchild ('RenderGraph|Output')

You can also access an immediate child of a node

.. code-block:: python

    from guerilla import _
    # Look up the Output inside the RenderGraph
    rg = _('RenderGraph')
    output = rg.getchild ('Output')

Scene Parsing
-------------

Now Let's see what is inside this node

.. code-block:: python

    from guerilla import pynode
    n = pynode('RenderGraph')
    for c in n.children():
        print c.name, type(c)

If we want to list lights

.. code-block:: python

    from guerilla import Document
    # Note:
    # type='Light' to filter lights only
    # recursive=True option to iterate deep in hierarchy
    for c in Document().children(type='Light',recursive=True):
        print c.name, type(c)

List all the shading overrides of the RenderGraph node

.. code-block:: python

	import guerilla
	for c in guerilla.pynode("RenderGraph").children ():
		for plug in c.plugs(type="AttributePlug") :
			print plug.getname ()

Dealing with attributes
-----------------------

Let's add a square light in our scene.

First we need to create a light then we change its Plug (named LightType) to 'square'

.. code-block:: python

    from guerilla import Modifier
    with Modifier() as mod:
        ln = mod.doc.loadfile('$(LIBRARY)/lights/pointlight.glight')[0]    
        ln.LightType.set('square')

Now we will store the artist name in a new attribute

.. code-block:: python
    
    from guerilla import Modifier, Plug, pynode
    with Modifier() as mod:
        ln = pynode('light1') # or create it...
        # create a Dynamic (saved in the scene) user plug (show up in the UI) 
        mod.createplug(ln, 'CreatedBy', 'user', 'string', Plug.Dynamic, 'Jimi Hendrix')

And now for experts (yeah!): 

* Add a node with a custom color attributes which will drive our light color

.. code-block:: python
    
    from guerilla import Modifier, Document, Plug, pynode
    with Modifier() as mod:
        lr = mod.createnode('lightRig')
        c = mod.createplug(lr, 'Color', 'user', 'color', Plug.Dynamic, [0, 1, 0])
        ln = pynode('light1') # or create it...
        # so now changing light rig color will change the light color
        ln.Color.connect(lr.Color)
        # let's print our light color (to check connection)
        print ln.Color.get()

* List all attributes of a node

.. code-block:: python
    
    from guerilla import Document
    # iterate over all cameras of the scene
    for camera in Document ().children (type='Camera'):
        print ("*** "+camera.getpath ())
        # iterate over all plugs
        for plug in camera.plugs ():
            print ("   "+plug.getname ())
            plugtype = plug.gettype ()
            if plugtype != None:
                print ("      type " + plugtype.getname ())
                plugvalue = plug.get ()
                print ("      value " + str (plugvalue))

* List all textures

.. code-block:: python
    
    from guerilla import Document
    # iterate over all nodes of the scene
    for node in Document ().children (recursive=True):
        # iterate over all plugs which type is 'texture'
        for plug in node.plugs ():
            plugtype = plug.gettype ()
            if plugtype != None and plugtype.getname () == 'texture':
                print (plug.get ())

or alternatively:

.. code-block:: python
    
    from guerilla import Document
    # iterate over all nodes of the scene
    for node in Document ().children (recursive=True):
        # iterate over all plugs which type is 'texture'
        for plug in node.plugs (typename='texture'):
            print (plug.get ())

Going further
-------------

* Try the next example in :doc:`index` 
* Explore the API documentation
 * :class:`~guerilla.Modifier`
 * :class:`~guerilla.Document`
 * :class:`~guerilla.Node`
 * :class:`~guerilla.Plug`
 * :meth:`~guerilla.pynode`