z-buffers explained

The very short explanation is that a z-buffer keeps track of what ''depth'' each pixel on the screen has been drawn at so far in the rendering process. For example, suppose you drew a polygon to the screen, and at one particular pixel, the z-value was 50. Then, if you draw another polygon, you check each pixel to see if it''s z-value is ''behind'' the old one. If it is, you don''t draw the pixel, but if not, you draw the pixel and update the z-buffer.

I hope this makes sense. You are pretty much keeping a running total of which colors should be on ''top'' in each pixel location. This way, you prevent a little overdraw, but you also mainly keep from overlapping parts of polygons that shouldn''t be visible from the perspective of your 3d viewpoint.

(Sorry, if that''s confusing. I''m tired )

Ok, thanks, that''s just what I needed.

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Daniel Netz, Sentinel Design

"I'm not stupid, I'm from Sweden" - Unknown