
634 Chapter 13 Containment Methods
13.5 Cylinders
The queries are organized with the point-in-cylinder query first, the computation of
bounding volumes second, and the merging of bounding volumes third. These are all
for finite cylinders.
13.5.1 Point in Cylinder
Let the cylinder axis be C + tD,whereC is the center of the cylinder, D is a direction
vector, and |t|≤h/2. The cylinder height is h and the cylinder radius is R. The query
point is P. Its component in the direction of the cylinder axis is T = D
.
(P − C).If
|T |>h/2, then P is outside the cylinder. If |T |≤h/2, it is not yet known whether P is
inside or outside. To be inside, if L is the cylinder ...