Invoking paint method in Java3D

Question

I have some example programs in using Java3D but none of them paints 'directly' on the canvas3D.
if i have a class that extends a Canvas3D how would i call the paint method, can i use this method to draw a 2D polygon on my canvas? (because i wanted to have 3D and 2D objects mixed).
how would i do this? are the points in terms of x, y, z?
can anyone help me with this?
thanks in advance

Answer 1

I've been trying to do this myself, snd it's a right pain in the arse.
To actually paint on the Canvas3D, when you override postRender(), you do all your stuff but it doesn't work until you call flush(). However, when I tied it (just drawing a simple rectange), my app slowed from 20fps to 2, which is a bit too much of a performance hit for my liking.
The J3D Repository overlay is fairly easy to set up, but for some reason the polygon it draws on is about 1 unit away from where you add it, so for a 1st person thing like I'm doing, it dissapears when you get too near a wall. In the end, i have just created my own by putting a texture on a cube just in front of the viewport.