Handles.BeginGUI

Description

Begin a 2D GUI block inside the 3D handle GUI.

The start of a GUILayout sequence of function calls. As expected the EndGUI is used to close these.

Additional resources: Handles.EndGUI.


GUI in the Scene View.

// Change the transform values for the selected object.
// When selected this script starts and the handleExample is managed.
// The HandlesGUI.BeginGUI() and EndGUI() functions allow the shieldArea
// to be changed back to five, which is the starting value.

using UnityEditor;
using UnityEngine;

[CustomEditor(typeof(HandleExample))]
class HandleExampleEditor : Editor
{
    protected virtual void OnSceneGUI()
    {
        HandleExample handleExample = (HandleExample)target;

        if (handleExample == null)
        {
            return;
        }

        Handles.color = Color.yellow;

        GUIStyle style = new GUIStyle();
        style.normal.textColor = Color.green;

        Vector3 position = handleExample.transform.position + Vector3.up * 2f;
        string posString = position.ToString();

        Handles.Label(position,
            posString + "\nShieldArea: " +
            handleExample.shieldArea.ToString(),
            style
        );

        Handles.BeginGUI();
        if (GUILayout.Button("Reset Area", GUILayout.Width(100)))
        {
            handleExample.shieldArea = 5;
        }
        Handles.EndGUI();

        Handles.DrawWireArc(
            handleExample.transform.position,
            handleExample.transform.up,
            -handleExample.transform.right,
            180,
            handleExample.shieldArea);

        handleExample.shieldArea =
            Handles.ScaleValueHandle(handleExample.shieldArea,
                handleExample.transform.position + handleExample.transform.forward * handleExample.shieldArea,
                handleExample.transform.rotation,
                1, Handles.ConeHandleCap, 1);
    }
}

Add a script that specifies the object that can be animated in the SceneView.

using UnityEngine;

[ExecuteInEditMode]
public class HandleExample : MonoBehaviour
{
    public float shieldArea = 5.0f;
}