[SOLVED] Handles.DoPositionHandle: Associate With GameObject Transform ?

Unity Engine
1

How do I associate a Handles.DoPositionHandle with a GameObject Transform such that the DoPositionHandle will appear at the GameObject’s position and the inspector field will read 0:0:0 ?

Currently I have only been able to figure out how to Draw the Handle at WorldSpace 0:0:0
In the following image, the cube is at WorldSpace 1:0:1. You’ll note the Handles at 0:0:0
2902079--213673--handles.png

I am able to calculate the actual the offset position, but am unsure how to reflect this in the inspector, as any calculations I make in OnGUI have compounding results… That is, the Handles quickly fly off screen.

What I want to be able to do is:

Draw the Handles starting at the Cube’sTransform Position and reflect a position of 0:0:0 in the inspector…
As I move the handles, the Position field should update to reflect the distance from the Cube.
Conversely, As I change the inspector values, the the handles should move in relation to the Cube

Can someone help correct my code?
Thanks

using UnityEditor;
using UnityEngine;

public class Mover : EditorWindow
{
    private GameObject _gameObject;
    private Vector3 _handleVector;
    private Vector3 _postionVector;
    private Vector3 _distanceVector;

    [MenuItem("Tools/Mover")]
    public static void OpenWindow()
    {
        var window = GetWindow<Mover>();
        window.titleContent = new GUIContent("Mover");
    }

    protected void OnEnable()
    {
        SceneView.onSceneGUIDelegate += OnSceneGUI;
    }

    protected void OnDisable()
    {
        SceneView.onSceneGUIDelegate -= OnSceneGUI;
    }

    protected void OnGUI()
    {
        EditorGUILayout.BeginVertical();
        _gameObject = (GameObject)EditorGUILayout.ObjectField("Game Object", _gameObject, typeof(GameObject), true);
        _postionVector = EditorGUILayout.Vector3Field("Position", _postionVector);
        _distanceVector = EditorGUILayout.Vector3Field("Distance to Game Object", _distanceVector);
        EditorGUILayout.EndVertical();
    }

    protected void OnInspectorUpdate()
    {
        if (SceneView.lastActiveSceneView != null)
        {
            SceneView.lastActiveSceneView.Repaint();
        }

        _handleVector = _postionVector;
        _distanceVector = GetDistanceVector(_gameObject.transform.position, _handleVector);


    }

    protected void OnSceneGUI(SceneView sceneview)
    {

        if (_gameObject)
        {
            EditorGUI.BeginChangeCheck();
            _handleVector = Handles.DoPositionHandle(_handleVector, Quaternion.identity);


            if (EditorGUI.EndChangeCheck())
            {
                _postionVector = _handleVector;
                _distanceVector = GetDistanceVector(_gameObject.transform.position, _handleVector);
            }
        }

        Repaint();

    }

    private Vector3 GetDistanceVector(Vector3 v1, Vector3 v2)
    {
        return new Vector3(Mathf.Abs(v1.x - v2.x), Mathf.Abs(v1.y - v2.y), Mathf.Abs(v1.z - v2.z));
    }



}
2

You will need to transform from and to the object’s local coordinate system.

Check out the public functions starting with Transform and InverseTransform.

3

Hey! If you know how to do this, don’t be coy. Because… believe me … I know what a “Transform” is.
Vector math is not my problem. The lackluster documentation is.

4

Solved with a bool.

Here’s The Code if it helps anyone:

using UnityEditor;
using UnityEngine;

public class Mover: EditorWindow
{
    private Vector3 _differenceVector;
    private GameObject _gameObject;
    private Vector3 _handleVector;
    private bool _isSet;
    private Vector3 _postionVector;

    private float _relativeX;
    private float _relativeY;
    private float _relativeZ;


    [MenuItem("Tools/Mover")]
    public static void OpenWindow()
    {
        var window = GetWindow<Mover>();
        window.titleContent = new GUIContent("Mover");
    }

    protected void OnEnable()
    {
        SceneView.onSceneGUIDelegate += OnSceneGUI;
    }

    protected void OnDisable()
    {
        SceneView.onSceneGUIDelegate -= OnSceneGUI;
    }

    protected void OnGUI()
    {
        EditorGUILayout.BeginVertical();
        _gameObject = (GameObject)EditorGUILayout.ObjectField("Game Object", _gameObject, typeof(GameObject), true);
        _postionVector = EditorGUILayout.Vector3Field("Position", _postionVector);

        if (_gameObject)
        {
            _differenceVector = _gameObject.transform.position * -1;
        }

        EditorGUILayout.EndVertical();
    }

    protected void OnInspectorUpdate()
    {
        if (SceneView.lastActiveSceneView != null)
        {
            SceneView.lastActiveSceneView.Repaint();
        }

        if (DetectChange(_postionVector, new Vector3(_relativeX, _relativeY, _relativeZ)))
        {
            _relativeX = _postionVector.x - _differenceVector.x;
            _relativeY = _postionVector.y - _differenceVector.y;
            _relativeZ = _postionVector.z - _differenceVector.z;

            _handleVector = new Vector3(_relativeX, _relativeY, _relativeZ);
        }

        if (!_gameObject)
        {
            _isSet = false;
        }
          
    }

    protected void OnSceneGUI(SceneView sceneview)
    {
        if (_gameObject)
        {
            EditorGUI.BeginChangeCheck();
            if (!_isSet)
            {
                _handleVector = Handles.DoPositionHandle(_gameObject.transform.position, Quaternion.identity);
                _isSet = true;
            }
            else
            {
                _handleVector = Handles.DoPositionHandle(_handleVector, Quaternion.identity);
            }

            if (EditorGUI.EndChangeCheck())
            {
                _postionVector = _handleVector + _differenceVector;
                _relativeX = _postionVector.x;
                _relativeY = _postionVector.y;
                _relativeZ = _postionVector.z;
            }
        }

        Repaint();
    }

    private bool DetectChange(Vector3 v1, Vector3 v2)
    {
        return !Mathf.Approximately(v1.x, v2.x) || !Mathf.Approximately(v1.y, v2.y) || !Mathf.Approximately(v1.z, v2.z);
    }
1 Like
5

@FuguFirecracker
Whoa Nelly!

That is some complicated code right there. I was having the same issue and I think I have found a much better solution. I know this was asked almost a year ago but I hope you come back and see this.

Basically when I am placing the handle, when I am calling the PositionHandle or DoPositionHandle method and I give the vector3 argument i also add the position of the object the component is on. THEN after i have called the PositionHandle method I subtract the objects position from it again!

Code is from a thing I am working on. Too lazy to change the variable names to match yours haha, so sorry about that. Just pay attention to the line in OnSceneGUI.

[CustomEditor(typeof(AttackSequence))]
public class HitBoxDrawer : Editor
{
    AttackSequence obj;

    private void OnEnable()
    {
        obj = (AttackSequence) target;
    }

    public override void OnInspectorGUI()
    {
        DrawDefaultInspector();
    }

    private void OnSceneGUI()
    {
        obj.hBox.centre = Handles.PositionHandle(obj.hBox.centre + obj.transform.position, Quaternion.identity) - obj.transform.position;
    }
4 Likes
6

Hey! Thanks for the post… That does seem much simpler :wink:

7

idc if this thread is 2 years old, thank u this was exactly what i was trying to figure out!!

8

Thank you for this! You just saved me a lot of time!
Edit: Still relevant and efficient.