fn PixelPos inputPoint3D =
(
local screen_width, screen_height
screen_width=RenderWidth as float
screen_height=RenderHeight as float

thePos = inputPoint3D * viewport.getTM()
screen_origin = mapScreenToView [0,0] (thePos.z) [screen_width,screen_height]
end_screen = mapScreenToView [screen_width,screen_height] (thePos.z) [screen_width,screen_height]
world_size = screen_origin-end_screen
x_aspect = screen_width/(abs world_size.x)
y_aspect = screen_height/(abs world_size.y)
screen_coords = point2 (x_aspect*(thePos.x-screen_origin.x)) (-(y_aspect*(thePos.y-screen_origin.y)))

return screen_coords
)