Graphics Reference
In-Depth Information
v
1
v
0
C
1
C
0
r
1
r
0
(a)
v
0
C
1
C
0
-
v
1
v
0
-
v
1
(b)
C
1
C
0
r
0
+
r
1
v
0
-
v
1
(c)
Figure 5.35
Recasting the moving sphere-sphere test as a ray intersection test. (a) The original
problem of intersecting a moving sphere against a moving sphere. (b) Transforming problem
into a moving sphere versus a stationary sphere. (c) Reduced to a ray test against a stationary
sphere of larger radius.
sphere into one with a combined radius of
r
0
r
1
(Figure 5.35c). The problem now
becomes that of intersecting a ray with a static sphere, for which a routine was given
in Section 5.3.2. The implementation is now straightforward.
+
int TestMovingSphereSphere(Sphere s0, Sphere s1, Vector v0, Vector v1, float &t)
{
// Expand sphere s1 by the radius of s0
s1.r += s0.r;
