DrawingScope

Description

Disposable helper struct for automatically setting and reverting Handles.color and/or Handles.matrix.

This struct allows you to temporarily set the value of Handles.color and/or Handles.matrix inside of a block of code and automatically revert them to their previous values when the scope is exited.

#pragma strict
// a custom editor that draws a labeled circle around the selected MeshRenderer in the scene view
@CustomEditor (MeshRenderer)
public class MeshRendererEditor extends Editor
{
    protected function OnSceneGUI ()
    {
        var meshRenderer: MeshRenderer = target as MeshRenderer;

        // get an orientation pointing from the selected object to the camera
        var cameraToTarget: Vector3 = Camera.current.transform.position - meshRenderer.transform.position;
        var billboardOrientation: Quaternion = Quaternion.LookRotation (cameraToTarget, Camera.current.transform.up);

        // set the handle matrix to the target's position, oriented facing the camera
        var matrix: Matrix4x4 = Matrix4x4.TRS (meshRenderer.transform.position, billboardOrientation, Vector3.one);
        var scope = new Handles.DrawingScope (Color.magenta, matrix);

        // draw a magenta circle around the selected object with a label at the top
        var size: Vector3 = meshRenderer.bounds.size;
        var radius: float = Mathf.Max (size.x, size.y, size.z);
        Handles.DrawWireArc (Vector3.zero, Vector3.forward, Vector3.right, 360f, radius);
        Handles.Label (Vector3.up * radius, meshRenderer.name);

        // JavaScript requires that you manually dispose of the scope when you are done with it
        scope.Dispose ();
    }
}

using UnityEditor;
using UnityEngine;

// a custom editor that draws a labeled circle around the selected MeshRenderer in the scene view
[CustomEditor(typeof(MeshRenderer))]
public class MeshRendererEditor : Editor
{
    protected virtual void OnSceneGUI()
    {
        MeshRenderer meshRenderer = (MeshRenderer)target;

        // get an orientation pointing from the selected object to the camera
        Vector3 cameraToTarget = Camera.current.transform.position - meshRenderer.transform.position;
        Quaternion billboardOrientation = Quaternion.LookRotation(cameraToTarget, Camera.current.transform.up);

        // set the handle matrix to the target's position, oriented facing the camera
        Matrix4x4 matrix = Matrix4x4.TRS(meshRenderer.transform.position, billboardOrientation, Vector3.one);
        using (new Handles.DrawingScope(Color.magenta, matrix))
        {
            // draw a magenta circle around the selected object with a label at the top
            Vector3 size = meshRenderer.bounds.size;
            float radius = Mathf.Max(size.x, size.y, size.z);
            Handles.DrawWireArc(Vector3.zero, Vector3.forward, Vector3.right, 360f, radius);
            Handles.Label(Vector3.up * radius, meshRenderer.name);
        }
    }
}

Properties

Constructors

Public Methods