Yes! There will be filled polygons in Art Of Destruction, the upcoming 3D game for the unexpanded Commodore VIC-20. Bresenham didn't do the trick but in the end it got very, very simple. It first does the filling with characters and then it fills up the edges pixel by pixel. There're about 2.5K left now for 3D calculations, special FX, sound and the most important thing about it all: gameplay. Most 3D calculations will probably boil down to points on circles and basic addition and subtraction.