Sets the rotation matrix in this homogeneous transformation matrix.
Source
void setRotation(Matrix3 r) {
final rStorage = r._m3storage;
_m4storage[0] = rStorage[0];
_m4storage[1] = rStorage[1];
_m4storage[2] = rStorage[2];
_m4storage[4] = rStorage[3];
_m4storage[5] = rStorage[4];
_m4storage[6] = rStorage[5];
_m4storage[8] = rStorage[6];
_m4storage[9] = rStorage[7];
_m4storage[10] = rStorage[8];
}