/// <summary>
/// Set the rotation from angle axis, angle is in radians
/// </summary>
/// <param name="axis"></param>
/// <param name="angle"></param>
/// <param name="x"></param>
/// <param name="y"></param>
/// <param name="z"></param>
/// <param name="w"></param>
private static void setRotation(ref Vector3 axis, ref float angle, out float x, out float y, out float z, out float w)
{
float d = axis.length();
float s = (float)System.Math.Sin(angle * 0.5f) / d;
x = axis.x * s;
y = axis.y * s;
z = axis.z * s;
w = (float)System.Math.Cos(angle * 0.5f);
}
