Unity editor extension to display a zoom indicator over the 2D scene view. Click it to reset to 100% zoom.

using System.Collections; using System.Collections.Generic; using UnityEngine; using UnityEditor; using System;

// Display a zoom indicator overlay on the 2D scene view. Click it to reset to 100% zoom [InitializeOnLoad] public static class SceneViewUIOverlay { static GUIStyle buttonStyle = new GUIStyle();

static SceneViewUIOverlay()
{
    SceneView.onSceneGUIDelegate += OnSceneGUI;
    buttonStyle.normal.textColor = Color.white;
}

static void OnSceneGUI(SceneView sceneView)
{
    if (!sceneView.in2DMode)
        return;

    // Calculate current zoom level
    float zoom = GetSceneViewHeight(sceneView) / (sceneView.camera.orthographicSize * 2f);

    // Display zoom indicator in top left corner; clicking the indicator resets to 100%
    Handles.BeginGUI();
    if (GUI.Button(new Rect(5, 5, 50, buttonStyle.lineHeight), $"{zoom * 100:N0}%", buttonStyle))
        SetSceneViewZoom(sceneView, 1f);
    Handles.EndGUI();
}

static float GetSceneViewHeight(SceneView sceneView)
{
    // Don't use sceneView.position.height, as it does not account for the space taken up by
    // toolbars.
    return sceneView.position.width / sceneView.camera.aspect;
}

static void SetSceneViewZoom(SceneView sceneView, float zoom)
{
    float orthoHeight = GetSceneViewHeight(sceneView) / 2f / zoom;

    // We can't set camera.orthographicSize directly, because SceneView overrides it
    // every frame based on SceneView.size, so set SceneView.size instead.
    //
    // See SceneView.GetVerticalOrthoSize for the source of these sqrts.
    //sceneView.size = orthoHeight * Mathf.Sqrt(2f) * Mathf.Sqrt(sceneView.camera.aspect);
    float size = orthoHeight * Mathf.Sqrt(2f) * Mathf.Sqrt(sceneView.camera.aspect);
    sceneView.LookAt(sceneView.pivot, sceneView.rotation, size);
}

}