Trouble with local3DToGlobal()

programming flash
1

I’ve been having some trouble understanding displayObject.local3DToGlobal() –

I want to determine the global (stage) x/y coordinates of a display object that’s existing in Flash 3D space – i.e. has a Z. I thought what I’d do is this (in pseudocode):

class myDisplayObject {

v3:Vector3D = new Vector3D(this.x, this.y, this.z);
pt:Point = this.local3DToGlobal(v3);
}

but apparently what I need to do is

class myDisplayObject {

v3:Vector3D = new Vector3D(this.x, this.y, this.z);
pt:Point = [COLOR="Red"]parent[/COLOR].local3DToGlobal(v3);
}

That is, the local3DToGlobal call must be called by the parent of the object. Is this true? Why? What am I not grokking here? If I do it from the object itself, it gives me wrong coordinates…

and this is also true if I do it outside a class structure as in

v3 = new Vector3D(myDisplayObject.x,myDisplayObject.y,myDisplayObject.z);
pt = myDisplayObject.local3DToGlobal(v3);

as opposed to

v3 = new Vector3D(myDisplayObject.x,myDisplayObject.y,myDisplayObject.z);
pt = this.local3DToGlobal(v3;

)

Thanks for any info – I can’t find this documented anywhere in the Adobe docs/examples…