Creating a new Item3D widget for use in EMScene3D
To create a new Item3D widget use must inherit from EMItem3D (you will need to import this class from emitem3d). EMItem3D is a new style class so you don't need to multiply inherit from object. To make a valid object you must re-implement several method and redefine two attributes
class(static) attribute: name, this gives a name for the new Item3D
class(static) attribute: nodetype, this classifies to Item3D. This name can be the same as other Itme3Ds. For example if I were making a torus Item3D, I would name this as "Shapenode" because that is what Cubes, Spheres, etc are named.
method: getEvalString(), this returns a string, which when evaled, creates an instance of this class. Generally you want this to create an instance of this class which is exactly the smae as the current instance because the purpose is for saving state.
method: getItemInspector(), this needs to return an inspector for this widget.
method: renderShape(), this implements the openGL code to actually render your object
For exmaple:
1 class EMNewItem(EMItem3D):
2 name = "myname"
3 nodetype = "mynodetype"
4 def __init__(self, parent=None, children=None, transform=None):
5 if not Transform: transform=transform()
6 EMItem3D.__init__(self,parent=parent,children=children,transform=transform)
7 self.item_inspector = None
8
9 def getEvalString(self):
10 return EMNewItem()
11
12 def getItemInspector(self):
13 if not self.item_inspector: self.iteminspector = EMNewItemInspector("New", self)
14 return self.item_inspector
15
16 def renderShape(self):
17 #Do open GL stuff
Enabling your new Item3D to be added to the 'add node' dialog
To allow your Item3D widget to be added to a scene graph using the 'add node' pushbutton(launches a dialog for adding nodes), you need to add two static functions to your Item3D class and add a few lines of code t the scene graph. Add these static functions: