Alternative method - Compose and render the scene first without the figure. Apply the render to a one-sided square primitive and position to fill the screen in exactly the same aspect as the original. Set the square to partial transparency in whatever percentage suits your purpose - try 50% and adjust as needed. Place the figure where you want it, and re-render with the semi-tran parent scene superimposed over the figure. Might produce the effects you want, with a bit of trial and error. Good luck with your image. . .