i managed to solve it in a bit complicated way.
i built a new camera, set orthographic projection for the original
camera, hid the overlay for the new camera, and all other objects for
the original camera.
i attached the script which draws a background. overlay can be done
similarly.
suggestions are welcome if a simpler solution exists.
best,
gabor
;;;;
(clear)
(ortho)
(define obj (build-cube))
(define bgr (build-plane))
(with-primitive bgr
(texture (load-texture "test.png"))
(scale #(2 1.5 1))
(hint-ignore-depth)
(hide 1)
(camera-hide 0))
(with-primitive obj
(camera-hide 1))
(define cam2 (build-camera))
(current-camera cam2)
