VertexSnapCustomEditor.cs

using UnityEngine;
using UnityEditor;
using System.Collections;

[CustomEditor(typeof(MeshFilter))]
[CanEditMultipleObjects]
public class VertexSnapCustomEditor : Editor {

    // Drawing with the Handles class only works from OnSceneGUI calls in Editor-classes,
    // so we have to relay from one such class.
    public void OnSceneGUI() {
        VertexSnapCustom vsc = VertexSnapCustom.GetInstance ();
        vsc.HandleOnSceneGUIDrawing ();
    }
}