Game Development Reference
In-Depth Information
The cell height
As our influence grid represents a three-dimensional area instead of just a two-dimensional
surface, a cell height is required in order to quantize geometry at varying heights. The fol-
lowing screenshot is an example of an influence map using a cell height of half a meter.
Notice that each cell used for debugging purposes is displayed as a plane oriented along the
x
axis but actually represents a cube that is one meter tall.
A cell height of 0.5 meters
The following is the same geometry but with an influence map configured for quarter meter
tall grid cells. While there isn't much difference in either configuration, setting a taller cell
height dramatically reduces the amount of memory the influence map costs, as the number
of total cells within the influence map will be reduced by half, in this case.
Here, the memory use of the influence map is double in comparison to the half-meter tall
version. Additionally, any operations that have to evaluate or manipulate large number of
grid cells will perform slower.
