Guard against tracking glitches that effect painting (icosa-foundatio…

…n#808)

* See if this prevents the glitching when CPU load is high

Assets/Scripts/Tools/FreePaintTool.cs

@@ -210,6 +210,15 @@ override public void AssignControllerMaterials(InputManager.ControllerName contr
 
         void PositionPointer()
         {
+            // Discard the pointer if the controller is exactly zero
+            // as it probably indicates the controller tracking stalled this frame
+            // TODO:Mikesky: See if can be done at input level
+            if (InputManager.m_Instance.GetControllerBehavior(InputManager.ControllerName.Brush).transform.position == Vector3.zero)
+            {
+                Debug.LogError($"Controller Glitch!");
+                return;
+            }
+
             // Angle the pointer according to the user-defined pointer angle.
             Transform rAttachPoint = InputManager.m_Instance.GetBrushControllerAttachPoint();
             Vector3 pos = rAttachPoint.position;