How can I rotate a bone from script? Applications: Move crane arm, point gun...

Questions & Answers
1

When a key is pressed, I want my bone to rotate. Here is my code so far:

using UnityEngine;
using System.Collections;

public class myAction : MonoBehaviour {

    // Use this for initialization
    void Start () {

    }

    // Update is called once per frame
    void Update () {
	    if(Input.GetKeyDown(KeyCode.A)){
		    GetComponent<Animation>().Play("animation1");
	    }
    }
    void LateUpdate(){
    	    if (Input.GetKeyDown (KeyCode.B)) {
		    (GetComponent<Transform>().Find("RootBone/Bone3")).eulerAngles = new Vector3 (0, 0, 90);
	    }

    }
}

After Edit, I get the following error:

NullReferenceException: Object reference not set to an instance of an object
rotateBones.LateUpdate () (at Assets/rotateBones.cs:20)

2

Try it like this:

using UnityEngine;
using System.Collections;

public class myAction : MonoBehaviour {

            public Transform bone;
	    // Use this for initialization
	    void Start () {
	        bone = GetComponent<Transform>().Find("RootBone/Bone3");
	    }
	
	    // Update is called once per frame
	    void Update () {
		    if(Input.GetKeyDown(KeyCode.A)){
			    GetComponent<Animation>().Play("animation1");
		    }
	    }
	    void LateUpdate(){
	    	    if (Input.GetKeyDown (KeyCode.B)) {
                            if(bone != null) {
                                    bone.eulerAngles = new Vector3 (0, 0, 90);
                            }
                            else {
                                 Debug.Log("bone is null!");
                            }
			    
		    }

	    }
}
3

I use script to animate Bone, I use character created with MAKEHUMAN software, i mean to rotate a bone to 90 degrees, the bone rotated well but not animated, the bone rotated instantly so we can’t see the rotating progress, i want this bone rotate process finish after 3 second, how to make that happen, this is my current code
using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class BoneAccess : MonoBehaviour
{
	public Transform bone;
    	// Start is called before the first frame update
    	void Start()
    	{
        	bone = GetComponent<Transform>().Find("MakeHuman default skeleton/root/spine05/spine04");
    	}

    	// Update is called once per frame
    	void Update()
    	{
        		if(bone != null) {
				bone.localEulerAngles = new Vector3 (130, 0, 0);
                             }
                             else {
				Debug.Log("bone is null!");
                             }
    	}
}