Locking rotation on local aix

Hello.
I need by physic body be able to rotate only by local X axis.

Z axis should be fixed; (same as rigitbody rotation constraints but local)
Y axis controlled by external script.

This is solution I have so far

Code (csharp):

1.  
2. Vector3 a = bike.transform.localRotation.eulerAngles;
3.  
4.         a.y = transform.localRotation.eulerAngles.y;       
5.         a.z = 0f;
6.  
7.         bike.transform.localRotation =  Quaternion.Euler(a);
8.  

But problem, that "bike" not able to rotate by X axis only from 90 to 270. It not able to flip back. I'm not very good with Quaternion's that's why I asking fro help. Thanks!

 

Little bump

I do not understand why unity does not allow rotation like 250, 0, 0 it modifies it to 290, 180, 180, but I have locked y, and z axis, and x rotation not able to be less than 270.

I tried implement something like this.

if(RoughlyEqual(a.z, 180f, 20f)) {
f.z += 180f;
f.y += 180f;
}
Now it able to be less then 270, but it has new issue it can simply stuck on x = 270. I do not know how to deal with it. I just have feeling that I do it wrong in first place. Thanks for reading.

 

I really surprised that I can not find solution for simple problem..

All I want to achieve is

localRotation.eulerAngles.x - controlled by UnityPhysics
localRotation.eulerAngles.y - controlled by me
localRotation.eulerAngles.z - always zero.




Current solution is looks like this, it can anyway can stuck on 270 or 90 degrees, but less frequently.
Everything work as expected except this "stucking" issue

Code (csharp):

1.  
2.  
3.     private float lastZ = 0f;
4.     private float lastX = 0f;
5.  
6.     public void FixRotation() {
7.  
8.  
9.         Vector3 a = bike.eulerRotation;
10.  
11.         if(lastX == 270f) {
12.             if(lastZ == 0f) {
13.                 a.z = 180f;
14.  
15.             } else {
16.                 a.z = 0f;
17.             }
18.  
19.         //  a.x = 272f;
20.  
21.         }
22.  
23.         if(lastX == 90f) {
24.             if(lastZ == 0f) {
25.                 a.z = 180f;
26.  
27.             } else {
28.                 a.z = 0f;
29.             }
30.         }
31.  
32.  
33.         if (RoughlyEqual (a.z, 180f, 10f)) {
34.             a.z = 180f;
35.             a.y = transform.localRotation.eulerAngles.y;
36.         } else {
37.             a.z = 0f;
38.             a.y = 180f +transform.localRotation.eulerAngles.y;
39.         }
40.  
41.         lastZ = a.z;
42.         lastX = a.x;
43.    
44.  
45.         bike.transform.localRotation = Quaternion.Euler (a);
46.    
47.  
48.     }
49.  

 

the thing with unity, converting that rotation for you it has to do with Gimble Lock, a serious pain for euler angles (transform rotation in unity's inspector).
btw, you can lock both rotation axes from the rigidbody and still modify them by script i guess.

 

That is not and option unfortunately.
rigidbody is global, so after my bike goes in the first turn it will be complete mess with axes.

 

you can add rigidbodies to the rest of your bike, and mark them as kinematic, and lock rotations, positions and such.

 

Event if rigidbodies inside other game object the constrains are global.

It tried both of your solutions yesterday... Buy I really appreciate that you trying to help. Thanks!

 

I have new Idea - rotate the track instead rotating bike.

There is RotateAround function.

But probably somebody can give quick tip, how to set rotation around point;

I was trying something like this

Code (csharp):

1.  
2. trackObject.transform.rotation = Quaternion.identity;
3. trackObject.transform.RotateAround (bike.transform.position, Vector3.up, 60f);
4.  

Bur result is really weird)