Game Development Reference
5.12 H EAT M AP
games gather a lot of statistical data regarding anything that happens while we are playing,
how many times we died, where we died, what was our weapon of choice, which paths did
the players take, what are the most significant choke points in a map, etc. All this informa-
tion is invaluable to game designers, level designers, it helps analyze and determine which
decisions made during game production where correct, which ones need to be reconsidered,
we may also find some surprising results.
Recording positional data is useful because it allows us to reconstruct a visual map of what
happened, using a heat map we can see the areas where some significant activity took place.
We will generate a heat map by drawing a gradient texture at every recorded point, our goal
is to draw the cumulative of the events we are interested in tracking, this means that we will
not only draw the gradient, but in order for the heat map to correctly display the accumula-
tion, we need to draw each point additively, this means the more points in the area, the more
the area will tend towards white as the pixel intensity increases.
Figure 72 - Radial gradient.
The addition of all the gradients at the points of interest will generate an intensity map, ran-
ging from transparent to full white. The intensity map will then look as a heat map, but it
will lack any color information.