Parsing vrml into a tree

[Mike C. Fletcher]

Hmm, there really isn't a built-in mechanism for getting "a plain tree" 
of the type you describe.  What you get from mcf.vrml is a directed 
graph of Node objects (that is, nodes can exist in multiple places 
within the tree):

 >>> from mcf.vrml import loader
 >>> sg = loader.load( r'Z:\worlds\temple\temple.wrl' )

Gives you the graph, which you can walk through fairly easily.  The root 
node handed back is a sceneGraph Node (or None if the load failed), it's 
most interesting attribute is "children", which is the collection of 
root nodes in the graph.

 >>> sg.children
[<Viewpoint('Camera01'): ['orientation', 'fieldOfView', 'position', 
'description']>, <PointLight('Omni01'): ['location', 'radius', 
'intensity', 'on', 'color']>, <PointLight('Omni02'): ['location', 
'radius', 'intensity', 'on', 'color']>, <NavigationInfo(''): 
['headlight']>, <Transform('Dome'): ['translation', 'children']>, 
<Transform('BathsTemple'): ['translation', 'children']>, 
<Transform('MushroomTemple'): ['translation', 'children']>]


For each node described there, you can walk through dealing with 
whatever attributes you need:

 >>> sg.children[-1].children[0]
<TimeSensor('MushroomTemple-TIMER'): ['loop', 'cycleInterval']>
 >>> sg.children[-1].children[0].loop = 1


If you really wanted to, you could pull out the attributes from the node 
objects:

 >>> sg.children[-1].children[0].attributeDictionary
{'loop': 1, 'cycleInterval': 3.3330000000000002}

And could then figure out how you want the other information (node type, 
DEF name, etceteras) stored in your simple tree.

Hope that helps,
Mike



Joonas Paalasmaa wrote:

> How can I parse vrml into a plain
> tree (dictionary or list) with mcf.vrml?
> 


-- 
_______________________________________
   Mike C. Fletcher
   http://members.rogers.com/mcfletch/