Irregular Z-buffer

<p>The irregular Z-buffer is an algorithm designed to solve the <a href="/facts/Visibility_problem/Wu1C49qu">visibility problem</a> in real-time 3-d computer graphics. It is related to the classical <a href="/facts/Z-buffer/HTyzcKbx">Z-buffer</a> in that it maintains a depth value for each image sample and uses these to determine which geometric elements of a scene are visible. The key difference, however, between the classical Z-buffer and the irregular Z-buffer is that the latter allows arbitrary placement of image samples in the <a href="/facts/Image_plane/46ydpCSb">image plane</a>, whereas the former requires samples to be arranged in a regular grid.
</p><p>These depth samples are explicitly stored in a two-dimensional spatial data structure. During <a href="/facts/Rasterization/QXfz5t7E">rasterization</a>, triangles are projected onto the image plane as usual, and the data structure is queried to determine which samples overlap each projected triangle. Finally, for each overlapping sample, the standard Z-compare and (conditional) frame buffer update are performed.
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Irregular Z-buffer open-in-new

Irregular Z-buffer