Game Development Reference
In-Depth Information
When modeling the impact between the club face and ball, we will make some simplifying
assumptions:
•
Any effects due to the club shaft or the golfer holding the club will be ignored. The club
head will treated as if it is moving through the air by itself.
•
At the point of impact, the club head will be traveling at a constant velocity. There will be
no net force acting on the club head.
Under these assumptions, the only things that will affect the impact are the mass of the
club head, the mass of the ball, the velocity of the club head at impact, and the angle of the
impact. Figure 7-3 shows a high-speed photography picture of the initial point of impact
between a club head and golf ball. The side of the ball in contact with the club face is being
compressed by the impact.
Figure 7-3.
A golf ball at the point of impact (Photo courtesy of Acushnet Company)
The impact of a golf ball and club head face is really just a simple collision, similar to those
we studied in Chapter 6. The ball is initially at rest either on the ground or on a tee. A simple
impact model, shown in Figure 7-4, assumes that the club head is traveling in the x-direction
with a velocity equal to
v
cx
. The swing is taken to be “ideal,” meaning that the club face strikes
the ball such that the line of action is perpendicular to the club face in the x-z plane.
α
v
cp
v
cn
α
z
v
cx
x
Figure 7-4.
Schematic of a club head—golf ball collision
