Fixed the deselecting of faces that are behind the face you clicked on

Scripts/Tools/SurfaceEditor.cs

@@ -180,24 +180,36 @@ void OnMouseDown (SceneView sceneView, Event e)
                 List<Polygon> raycastHits = csgModel.RaycastBuiltPolygonsAll(ray).Select(hit => csgModel.GetSourcePolygon(hit.Polygon.UniqueIndex)).Where(item => item != null).ToList();
                 Polygon sourcePolygon = null;
 
-                // Walk through the hits from front to back and find if any of them are in the selection set
-                for (int i = 0; i < raycastHits.Count; i++)
+                // User is trying to multiselect, let's not make life difficult for them by only accepting the nearest polygon
+                if (SabreInput.IsModifier(e, EventModifiers.Shift))
                 {
-                    if(selectedSourcePolygons.Contains(raycastHits[i]))
+                    // Use the first polygon that was hit
+                    if (raycastHits.Count > 0)
                     {
-                        sourcePolygon = raycastHits[i];
-                        break;
+                        sourcePolygon = raycastHits[0];
                     }
                 }
-
-                // None of the hit polygons are in the selection set, so just use the first hit polygon if it's available
-                if(sourcePolygon == null && raycastHits.Count >= 1)
+                else
                 {
-                    sourcePolygon = raycastHits[0];
+                    // Walk through the hits from front to back and find if any of them are in the selection set
+                    for (int i = 0; i < raycastHits.Count; i++)
+                    {
+                        if (selectedSourcePolygons.Contains(raycastHits[i]))
+                        {
+                            sourcePolygon = raycastHits[i];
+                            break;
+                        }
+                    }
+
+                    // None of the hit polygons are in the selection set, so just use the first hit polygon if it's available
+                    if (sourcePolygon == null && raycastHits.Count >= 1)
+                    {
+                        sourcePolygon = raycastHits[0];
+                    }
                 }
 
                 // If a polygon has been hit
-				if(sourcePolygon != null)
+                if (sourcePolygon != null)
                 {
                     // Reset drag values
                     totalDelta = Vector2.zero;