Game Physics Engine Development, 2nd Edition

12.2 Broad-Phase Collision Detection 255

Broad phase

detects potential collisions

Narrow phase

checks each potential

collision for actual collision

FIGURE 12.1 The collision detection pipeline.

To reduce the time taken for each check, the geometry is typically simplified. A

special geometry just for collision detection is often created, making contact tests far

simpler. This is primarily an issue when we get to narrow-phase collision detection,

so it will be discussed in Section 13.1.

12.2 Broad-Phase Collision Detection

The first phase of collision detection is tasked with quickly filtering down all the possi-

ble collisions into a much smaller set. This ...