unity rotations

 ////////////////////////////////////////////////////////
 // rotate a point around another point using quaternions
 
 // set quaterion by vector
 var quat = Quaternion.LookRotation(Vector3 forward, Vector3 upwards = Vector3.up);
 
 // set quaternion by angle
 var quat = Quaternion.AngleAxis(float angle, Vector3 axis);
 
 // rotate around pivit point
 Vector3 RotateAroundPoint(Vector3 point, Vector3 pivot, Quaternion angle)
 {
     return angle * ( point - pivot) + pivot;
 }