crossVectors method
Sets this vector to cross product of a and b.
Implementation
Vector3 crossVectors(Vector3 a, Vector3 b) {
var ax = a.x, ay = a.y, az = a.z;
var bx = b.x, by = b.y, bz = b.z;
x = ay * bz - az * by;
y = az * bx - ax * bz;
z = ax * by - ay * bx;
return this;
}