public Mat3 FromRotationAxis(Vec3 axis, float angle)
        {
            Quat quaternion = Quat.FromRotationAxis(axis, angle);

            return(FromQuaternion(quaternion));
        }
 public RigidTransform3(Vec3 position)
 {
     this.position = position;
     rotation      = Quat.Identity;
 }
 public RigidTransform3(Quat orienation)
 {
     position = new Vec3();
     rotation = orienation;
 }
 public RigidTransform3(Quat orienation, Vec3 position)
 {
     rotation      = orienation;
     this.position = position;
 }