Quaternion substraction issue

I'm trying to get the difference between two quaternions but as it often happens with quaternions something is going wrong and i don't understand what.

Code (CSharp):

1.  
2. private void Carry()
3.     {
4.         if (pickedUp)
5.         {
6.             Vector3 currPos = rb.position;
7.             Vector3 targetPos = pointRb.position;
8.             rb.velocity = (targetPos - currPos) * step;
9.            
10.             if (Input.GetMouseButtonDown(0))
11.             {
12.                 iniRot = rb.rotation;
13.                 print("iniRot   " + iniRot.eulerAngles);
14.                
15.                 FPSController.instance.lockCamera = true;
16.                 rb.angularDrag = 10;
17.             }
18.             if (Input.GetMouseButtonUp(0))
19.             {
20.                 FPSController.instance.lockCamera = false;
21.                 rb.angularDrag = 1;
22.                 rotDiff = rb.rotation * Quaternion.Inverse(iniRot);
23.                
24.                 print("currRot   " + rb.rotation.eulerAngles);
25.                 print("rotDiff   " + rotDiff.eulerAngles);
26.             }
27.             if (Input.GetMouseButton(0))
28.             {  
29.                 float x = Input.GetAxis("Mouse X");
30.                 float y = Input.GetAxis("Mouse Y");
31.                
32.                 Vector3 mouseDir = new Vector3(x, y, 0);
33.                 mouseDir = cam.TransformDirection(mouseDir);
34.                
35.                
36.                 Vector3 axis = Vector3.Cross(mouseDir, cam.forward).normalized;
37.                
38.                 Debug.DrawRay(transform.position, axis * 10f, Color.magenta);
39.  
40.                 float angle = step * rotSpeed;
41.  
42.  
43.                 Vector3 velocity = angle * axis * Mathf.Rad2Deg;
44.  
45.                 rb.angularVelocity += velocity;
46.             }
47.             else
48.             {
49.                 Quaternion currRot = rb.rotation;
50.                 Quaternion targetRot = pointRb.rotation;
51.                 targetRot = pointRb.rotation * rotDiff;
52.        
53.                 Quaternion diff = targetRot * Quaternion.Inverse(currRot);
54.                
55.                 Vector3 angularDisplacement = PhysicsHelper.QuaternionToAngularVelocity(diff);
56.                 Vector3 angularSpeed = angularDisplacement * step;
57.                
58.                 rb.angularVelocity = angularSpeed;
59.             }
60.         }
61.     }

In this code i'm trying to store rigidbody rotation in the moment when i press LMB and substract it from rotation in the moment when i release LMB. The output is pretty strange and i don't get whether it is the problem of quaternion representation in eulerangles or just my fault somewhere.

 

I think maybe you want:

Code (CSharp):

1. Quaternion diff = Quaternion.FromToRotation(targetRot, currRot);

 

I tried that but sadly the result wasn't right. Does it do the same as manually substracting quaternions? If so, then maybe substraction wasn't a problem...