private void DrawMask(Camera cam)
 {
     GCommon.ForEachTerrain(instance.GroupId, (t) =>
     {
         GLivePreviewDrawer.DrawTerrainMask(t, cam);
     });
 }
 private void DrawMask(Camera cam)
 {
     GCommon.ForEachTerrain(painter.GroupId, (t) =>
     {
         if (t.TerrainData == null)
         {
             return;
         }
         if (painter.ActivePainter is GMaskPainter)
         {
             GLivePreviewDrawer.DrawMask4ChannelsLivePreview(t, cam, t.TerrainData.Mask.MaskMap, GCommon.UnitRect);
         }
         else
         {
             GLivePreviewDrawer.DrawTerrainMask(t, cam);
         }
     });
 }