axis property
axis of rotation.
Implementation
Vector3 get axis {
final double den = 1.0 - (_qStorage[3] * _qStorage[3]);
if (den < 0.0005) {
// 0-angle rotation, so axis does not matter
return new Vector3.zero();
}
final double scale = 1.0 / math.sqrt(den);
return new Vector3(
_qStorage[0] * scale, _qStorage[1] * scale, _qStorage[2] * scale);
}