
1. Compute-Based Tiled Culling 445
Max Z
Min Z
Scene geometry
(a)
Max Z
Min Z
Half Z
(b)
Max Z
Min Z2
Max Z2
Min Z
(c)
Figure 1.4. Depth discontinuity optimization strategies. (a) Scene depth discontinuities
can cause a large depth range in the tile bounding volume. (b) The Half Z method splits
the depth range in half and culls against the two ranges. (c) The Modified Half Z method
calculates a second minimum and maximum, bounded by the Half Z value.
1.4.2 Depth Discontinuities
Having covered the basic optimizations already present in the code from Sec-
tion 1.3, additional optimizations will now be presented, starting with those for
discontinuities in scene depth. ...