multiplyQuaternions method
Multiply a
by b
Implementation
Quat multiplyQuaternions(Quat a, Quat b ) {
double qax = a.x, qay = a.y, qaz = a.z, qaw = a.w;
double qbx = b.x, qby = b.y, qbz = b.z, qbw = b.w;
x = qax * qbw + qaw * qbx + qay * qbz - qaz * qby;
y = qay * qbw + qaw * qby + qaz * qbx - qax * qbz;
z = qaz * qbw + qaw * qbz + qax * qby - qay * qbx;
w = qaw * qbw - qax * qbx - qay * qby - qaz * qbz;
return this;
}