diff --git a/cura/Layer.py b/cura/Layer.py
index 03b96f4f3a..4e38a6eba9 100644
--- a/cura/Layer.py
+++ b/cura/Layer.py
@@ -67,9 +67,11 @@ class Layer:
     def createJumps(self):
         return self.createMeshOrJumps(False)
 
+    # Defines the two triplets of local point indices to use to draw the two faces for each line segment in createMeshOrJump
+    __index_pattern = numpy.array([[0, 3, 2, 0, 1, 3]], dtype = numpy.int32 )
+
     def createMeshOrJumps(self, make_mesh):
         builder = MeshBuilder()
-        index_pattern = numpy.array([[0, 3, 2, 0, 1, 3]], dtype = numpy.int32 )
         
         line_count = 0
         if make_mesh:
@@ -106,8 +108,8 @@ class Layer:
 
             # Create 4 points to draw each line segment, points +- normals results in 2 points each. Reshape to one point per line
             f_points = numpy.concatenate((points-normals, points+normals), 1).reshape((-1, 3))
-            # index_pattern defines which points to use to draw the two faces for each lines egment, the following linesegment is offset by 4 
-            f_indices = ( index_pattern + numpy.arange(0, 4 * len(normals), 4, dtype=numpy.int32).reshape((-1, 1)) ).reshape((-1, 3))
+            # __index_pattern defines which points to use to draw the two faces for each lines egment, the following linesegment is offset by 4 
+            f_indices = ( self.__index_pattern + numpy.arange(0, 4 * len(normals), 4, dtype=numpy.int32).reshape((-1, 1)) ).reshape((-1, 3))
             f_colors = numpy.repeat(polygon.mapLineTypeToColor(line_types), 4, 0)
 
             builder.addFacesWithColor(f_points, f_indices, f_colors)
diff --git a/cura/LayerPolygon.py b/cura/LayerPolygon.py
index b063660198..c534592757 100644
--- a/cura/LayerPolygon.py
+++ b/cura/LayerPolygon.py
@@ -63,7 +63,7 @@ class LayerPolygon:
         
 
     def build(self, vertex_offset, index_offset, vertices, colors, indices):
-        if (self._build_cache_line_mesh_mask == None) or (self._build_cache_needed_points == None ):
+        if (self._build_cache_line_mesh_mask is None) or (self._build_cache_needed_points is None ):
             self.buildCache()
             
         line_mesh_mask = self._build_cache_line_mesh_mask
diff --git a/plugins/CuraEngineBackend/Cura.proto b/plugins/CuraEngineBackend/Cura.proto
index af4b40859d..d38f95035f 100644
--- a/plugins/CuraEngineBackend/Cura.proto
+++ b/plugins/CuraEngineBackend/Cura.proto
@@ -61,7 +61,7 @@ message Polygon {
     float line_width = 3; // The width of the line being laid down
 }
 
-message LayerOptimized { 
+message LayerOptimized {
     int32 id = 1;
     float height = 2; // Z position
     float thickness = 3; // height of a single layer
@@ -71,10 +71,15 @@ message LayerOptimized {
 
 
 message PathSegment {
-	int32 ordinal = 1; // The absolute ordinal of this line segment
-    bytes line_type = 2; // Type of line segment as an unsigned char array of length 1 or N, where N is the number of line segments in this path
-    bytes points = 3; // The points defining the line segments, bytes of int64[2]? array of length N+1
-    bytes line_width = 4; // The widths of the line segments as bytes of a float?/int32? array of length 1 or N
+    int32 extruder = 1; // The extruder used for this path segment
+    enum PointType {
+        Point2D = 0;
+        Point3D = 1;
+    }
+    PointType point_type = 2;
+    bytes points = 3; // The points defining the line segments, bytes of int64[2/3]? array of length N+1
+    bytes line_type = 4; // Type of line segment as an unsigned char array of length 1 or N, where N is the number of line segments in this path
+    bytes line_width = 5; // The widths of the line segments as bytes of a float? array of length 1 or N
 }