Let Canvas3D draw in another Graphics object

Hello all,

I have the following problem: I want to use a library which contains a
class that extends already java.awt.Canvas. I want to use this class
as a canvas, since it provides many useful features. However, Java3D
requires a Canvas3D object. My plan was, to subclass Canvas3D and
override paint, so that it doesn't use its own Graphics object, but
that of the other Canvas class. Something like this:

class NewCanvas extends OtherCanvas {
    private MyCanvas3D canvas3d;
    private Graphics graphics;

    private class MyCanvas3D extends Canvas3D {
        public void paint(Graphics g) {
            super.paint(graphics);
        }
    }
    ...
}

I know, that this is not nice, and it doesn't work either. So maybe
some of you can tell me how something like this can be done in a
proper way.

Thanks a lot