Z-Buffering

[03ricr]

hello, i'm trying to make a 3d engine but i want to implement z-buffering on the faces - i use 3 point poly faces.

does anyone know the algorithm for it or something like that??

[Jomiq]

I don't know any algorithms, but i guess a z-buffert would consist mainly on two things:

1. a device to determine wether a surface is facing towards the beholder. surfaces facing away are not displayed.

2. a device for determing the distances between the eyepoint and the surface. surfaces closer to the eye is drawn on top of surfaces farther away.

for point 1 you will only have to know the normal for the surface.

point two will be trickier, since some polygons ar partly hidden, and can go into each other.. I think that calculating on the center of the polygon is not enough in most cases... what i guess you need to do is find the intersections, then calculate them using massive trigonometry... or something.

many Z buffers, for example the one in open gl, have problems with intersections. edges get zig-zagged along the intersections from some angles, and I seriously have no idea of why and what to do about it. It makes me believe however that the intersections are the hard part.

cheers mate.