HandleUtility.DistanceToCone

Parameters

Returns

float Distance from mouse to cone in pixels.

Description

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

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

Returns zero when mouse pointer is directly over the cone.

Uses the current camera to determine the distance.

using UnityEngine;
using UnityEditor;

public class ExampleScript : MonoBehaviour
{
}

// Displays cone in scene view, and distance from mouse
// to the cone.
[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 cone in scene
        Handles.color = Color.yellow;
        Handles.ConeHandleCap(0, position, rotation, size, Event.current.type);
        // calculate distance from mouse to cone, and display it
        var distance = HandleUtility.DistanceToCone(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, DistanceToCube, DistanceToLine.