HandleUtility.DistanceToCube

Parameters

Returns

float Distance from mouse to cube in pixels.

Description

Returns the distance in pixels from the mouse pointer to a cube.

Calculates the screen space distance from the mouse pointer to a cube at given world space position with the given rotation and size.

Returns zero when mouse pointer is directly over the cube.

Uses the current camera to determine the distance.

using UnityEngine;
using UnityEditor;

public class ExampleScript : MonoBehaviour
{
}

// Displays cube in scene view, and distance from mouse
// to the cube.
[CustomEditor(typeof(ExampleScript))]
public class ExampleEditor : Editor
{
    public void OnSceneGUI()
    {
        var t = target as ExampleScript;
        var tr = t.transform;
        var position = tr.position;
        var rotation = tr.rotation;
        var size = 1.0f;
        // draw a cube in scene
        Handles.color = Color.yellow;
        Handles.CubeHandleCap(0, position, rotation, size, Event.current.type);
        // calculate distance from mouse to cube, and display it
        var distance = HandleUtility.DistanceToCube(position, rotation, size);
        GUI.color = Color.black;
        Handles.Label(position, distance.ToString("F0"));
        // make scene view repaint on mouse move
        if (Event.current.type == EventType.MouseMove)
            Event.current.Use();
    }
}

.

Additional resources: DistanceToCircle, DistanceToCone, DistanceToLine.