|What is a Z-Buffer|
(3/5/00 4:13:01 pm)
Can someone explain what a Zbuffer is and what it's good for.
(3/5/00 7:08:19 pm)
It's used in 3D apps and is used so the polygons currently not in view are not drawn.
(3/6/00 6:58:49 am)
That's not really what it does, the Z buffer takes care of a problem called Z-fighting that occurs when two polygons have the same depth (z), if they do and a z buffer is not available, it will most likely flip between the two polygons and it's gonna look odd.
A z buffer stores the polygon depth and helps prevent z-fighting from occuring, it can also be used for hidden surface removal.
Edited by Daniel Netz at: 3/6/00 6:58:49 am
(3/6/00 11:27:30 pm)
Actually Peter is right. Z-buffering is an algorithm that is used to help with hidden surface removal.
There is an alternate to the z-buffer algorithm, called the painter's algorithm. Its more complicated than z-buffers, but less intensive on the cpu.
Technically, a z buffer is
an screen buffer the same size as the video screen. For example, 640 x
480 matrix of 16 bit numbers for a 16 bit z-buffer, or integers, or whatever
preicsion is needed.
As for a pixel having two or more identical z values, then one would need to increase the precision of the z-buffer.