diff --git a/cura/BuildVolume.py b/cura/BuildVolume.py
index f071bf4057..efc306c32d 100644
--- a/cura/BuildVolume.py
+++ b/cura/BuildVolume.py
@@ -36,6 +36,7 @@ class BuildVolume(SceneNode):
         self._disallowed_area_mesh = None
 
         self.setCalculateBoundingBox(False)
+        self._volume_aabb = None
 
         self._active_container_stack = None
         Application.getInstance().globalContainerStackChanged.connect(self._onGlobalContainerStackChanged)
@@ -99,7 +100,7 @@ class BuildVolume(SceneNode):
         mb.addLine(Vector(min_w, max_h, min_d), Vector(min_w, max_h, max_d), color = self.VolumeOutlineColor)
         mb.addLine(Vector(max_w, max_h, min_d), Vector(max_w, max_h, max_d), color = self.VolumeOutlineColor)
 
-        self.setMeshData(mb.getData())
+        self.setMeshData(mb.build())
 
         mb = MeshBuilder()
         mb.addQuad(
@@ -108,10 +109,10 @@ class BuildVolume(SceneNode):
             Vector(max_w, min_h - 0.2, max_d),
             Vector(min_w, min_h - 0.2, max_d)
         )
-        self._grid_mesh = mb.getData()
         for n in range(0, 6):
-            v = self._grid_mesh.getVertex(n)
-            self._grid_mesh.setVertexUVCoordinates(n, v[0], v[2])
+            v = mb.getVertex(n)
+            mb.setVertexUVCoordinates(n, v[0], v[2])
+        self._grid_mesh = mb.build()
 
         disallowed_area_height = 0.1
         disallowed_area_size = 0
@@ -136,11 +137,11 @@ class BuildVolume(SceneNode):
                     size = 0
                 disallowed_area_size = max(size, disallowed_area_size)
 
-            self._disallowed_area_mesh = mb.getData()
+            self._disallowed_area_mesh = mb.build()
         else:
             self._disallowed_area_mesh = None
 
-        self._aabb = AxisAlignedBox(minimum = Vector(min_w, min_h - 1.0, min_d), maximum = Vector(max_w, max_h, max_d))
+        self._volume_aabb = AxisAlignedBox(minimum = Vector(min_w, min_h - 1.0, min_d), maximum = Vector(max_w, max_h, max_d))
 
         skirt_size = 0.0
 
@@ -158,6 +159,9 @@ class BuildVolume(SceneNode):
 
         Application.getInstance().getController().getScene()._maximum_bounds = scale_to_max_bounds
 
+    def getBoundingBox(self):
+        return self._volume_aabb
+
     def _onGlobalContainerStackChanged(self):
         if self._active_container_stack:
             self._active_container_stack.propertyChanged.disconnect(self._onSettingPropertyChanged)
diff --git a/cura/ConvexHullDecorator.py b/cura/ConvexHullDecorator.py
index 39cdc36232..9fccd46988 100644
--- a/cura/ConvexHullDecorator.py
+++ b/cura/ConvexHullDecorator.py
@@ -1,116 +1,217 @@
 from UM.Scene.SceneNodeDecorator import SceneNodeDecorator
 from UM.Application import Application
 
+from UM.Math.Polygon import Polygon
+from . import ConvexHullNode
+
+import numpy
 
 ##  The convex hull decorator is a scene node decorator that adds the convex hull functionality to a scene node.
 #   If a scene node has a convex hull decorator, it will have a shadow in which other objects can not be printed.
 class ConvexHullDecorator(SceneNodeDecorator):
     def __init__(self):
         super().__init__()
-        self._convex_hull = None
-
-        # In case of printing all at once this is the same as the convex hull.
-        # For one at the time this is the area without the head.
-        self._convex_hull_boundary = None 
-
-        # In case of printing all at once this is the same as the convex hull.
-        # For one at the time this is area with intersection of mirrored head
-        self._convex_hull_head = None
-
-        # In case of printing all at once this is the same as the convex hull.
-        # For one at the time this is area with intersection of full head
-        self._convex_hull_head_full = None
 
         self._convex_hull_node = None
-        self._convex_hull_job = None
-
-        # Keep track of the previous parent so we can clear its convex hull when the object is reparented
-        self._parent_node = None
+        self._init2DConvexHullCache()
 
         self._global_stack = None
         Application.getInstance().globalContainerStackChanged.connect(self._onGlobalStackChanged)
+        Application.getInstance().getController().toolOperationStarted.connect(self._onChanged)
+        Application.getInstance().getController().toolOperationStopped.connect(self._onChanged)
+
         self._onGlobalStackChanged()
-        #Application.getInstance().getMachineManager().activeProfileChanged.connect(self._onActiveProfileChanged)
-        #Application.getInstance().getMachineManager().activeMachineInstanceChanged.connect(self._onActiveMachineInstanceChanged)
-        #self._onActiveProfileChanged()
 
     def setNode(self, node):
+        previous_node = self._node
+        if previous_node is not None and node is not previous_node:
+            previous_node.transformationChanged.connect(self._onChanged)
+            previous_node.parentChanged.connect(self._onChanged)
+
         super().setNode(node)
-        self._parent_node = node.getParent()
-        node.parentChanged.connect(self._onParentChanged)
+
+        self._node.transformationChanged.connect(self._onChanged)
+        self._node.parentChanged.connect(self._onChanged)
+
+        self._onChanged()
 
     ## Force that a new (empty) object is created upon copy.
     def __deepcopy__(self, memo):
-        copy = ConvexHullDecorator()
-        return copy
+        return ConvexHullDecorator()
 
-    ##  Get the unmodified convex hull of the node
+    ##  Get the unmodified 2D projected convex hull of the node
     def getConvexHull(self):
-        return self._convex_hull
+        if self._node is None:
+            return None
+
+        hull = self._compute2DConvexHull()
+        if self._global_stack and self._node:
+            if self._global_stack.getProperty("print_sequence", "value") == "one_at_a_time" and not self._node.getParent().callDecoration("isGroup"):
+                hull = hull.getMinkowskiHull(Polygon(numpy.array(self._global_stack.getProperty("machine_head_polygon"), numpy.float32)))
+        return hull
 
     ##  Get the convex hull of the node with the full head size
     def getConvexHullHeadFull(self):
-        if not self._convex_hull_head_full:
-            return self.getConvexHull()
-        return self._convex_hull_head_full
+        if self._node is None:
+            return None
+
+        return self._compute2DConvexHeadFull()
 
     ##  Get convex hull of the object + head size
     #   In case of printing all at once this is the same as the convex hull.
     #   For one at the time this is area with intersection of mirrored head
     def getConvexHullHead(self):
-        if not self._convex_hull_head:
-            return self.getConvexHull()
-        return self._convex_hull_head
+        if self._node is None:
+            return None
+
+        if self._global_stack:
+            if self._global_stack.getProperty("print_sequence", "value") == "one_at_a_time" and not self._node.getParent().callDecoration("isGroup"):
+                return self._compute2DConvexHeadMin()
+        return None
 
     ##  Get convex hull of the node
     #   In case of printing all at once this is the same as the convex hull.
     #   For one at the time this is the area without the head.
     def getConvexHullBoundary(self):
-        if not self._convex_hull_boundary:
-            return self.getConvexHull()
-        return self._convex_hull_boundary
+        if self._node is None:
+            return None
 
-    def setConvexHullBoundary(self, hull):
-        self._convex_hull_boundary = hull
+        if self._global_stack:
+            if self._global_stack("print_sequence") == "one_at_a_time" and not self._node.getParent().callDecoration("isGroup"):
+                # Printing one at a time and it's not an object in a group
+                return self._compute2DConvexHull()
+        return None
 
-    def setConvexHullHeadFull(self, hull):
-        self._convex_hull_head_full = hull
+    def recomputeConvexHull(self):
+        controller = Application.getInstance().getController()
+        root = controller.getScene().getRoot()
+        if self._node is None or controller.isToolOperationActive() or not self.__isDescendant(root, self._node):
+            if self._convex_hull_node:
+                self._convex_hull_node.setParent(None)
+                self._convex_hull_node = None
+            return
 
-    def setConvexHullHead(self, hull):
-        self._convex_hull_head = hull
-
-    def setConvexHull(self, hull):
-        self._convex_hull = hull
-        if not hull and self._convex_hull_node:
+        convex_hull = self.getConvexHull()
+        if self._convex_hull_node:
+            if self._convex_hull_node.getHull() == convex_hull:
+                return
             self._convex_hull_node.setParent(None)
-            self._convex_hull_node = None
-
-    def getConvexHullJob(self):
-        return self._convex_hull_job
-
-    def setConvexHullJob(self, job):
-        self._convex_hull_job = job
-
-    def getConvexHullNode(self):
-        return self._convex_hull_node
-
-    def setConvexHullNode(self, node):
-        self._convex_hull_node = node
+        hull_node = ConvexHullNode.ConvexHullNode(self._node, convex_hull, root)
+        self._convex_hull_node = hull_node
 
     def _onSettingValueChanged(self, key, property_name):
         if key == "print_sequence" and property_name == "value":
             self._onChanged()
 
-    def _onChanged(self, *args):
-        if self._convex_hull_job:
-            self._convex_hull_job.cancel()
-        self.setConvexHull(None)
+    def _init2DConvexHullCache(self):
+        # Cache for the group code path in _compute2DConvexHull()
+        self._2d_convex_hull_group_child_polygon = None
+        self._2d_convex_hull_group_result = None
 
-    def _onParentChanged(self, node):
-        # Force updating the convex hull of the parent group if the object is in a group
-        if self._parent_node and self._parent_node.callDecoration("isGroup"):
-            self._parent_node.callDecoration("setConvexHull", None)
-        self._parent_node = self.getNode().getParent()
+        # Cache for the mesh code path in _compute2DConvexHull()
+        self._2d_convex_hull_mesh = None
+        self._2d_convex_hull_mesh_world_transform = None
+        self._2d_convex_hull_mesh_result = None
+
+    def _compute2DConvexHull(self):
+        if self._node.callDecoration("isGroup"):
+            points = numpy.zeros((0, 2), dtype=numpy.int32)
+            for child in self._node.getChildren():
+                child_hull = child.callDecoration("_compute2DConvexHull")
+                if child_hull:
+                    points = numpy.append(points, child_hull.getPoints(), axis = 0)
+
+                if points.size < 3:
+                    return None
+            child_polygon = Polygon(points)
+
+            # Check the cache
+            if child_polygon == self._2d_convex_hull_group_child_polygon:
+                return self._2d_convex_hull_group_result
+
+            # First, calculate the normal convex hull around the points
+            convex_hull = child_polygon.getConvexHull()
+
+            # Then, do a Minkowski hull with a simple 1x1 quad to outset and round the normal convex hull.
+            # This is done because of rounding errors.
+            rounded_hull = self._roundHull(convex_hull)
+
+            # Store the result in the cache
+            self._2d_convex_hull_group_child_polygon = child_polygon
+            self._2d_convex_hull_group_result = rounded_hull
+
+            return rounded_hull
+
+        else:
+            rounded_hull = None
+            if self._node.getMeshData():
+                mesh = self._node.getMeshData()
+                world_transform = self._node.getWorldTransformation()
+
+                # Check the cache
+                if mesh is self._2d_convex_hull_mesh and world_transform == self._2d_convex_hull_mesh_world_transform:
+                    return self._2d_convex_hull_mesh_result
+
+                vertex_data = mesh.getConvexHullTransformedVertices(world_transform)
+                # Don't use data below 0.
+                # TODO; We need a better check for this as this gives poor results for meshes with long edges.
+                vertex_data = vertex_data[vertex_data[:,1] >= 0]
+
+                if len(vertex_data) >= 4:
+                    # Round the vertex data to 1/10th of a mm, then remove all duplicate vertices
+                    # This is done to greatly speed up further convex hull calculations as the convex hull
+                    # becomes much less complex when dealing with highly detailed models.
+                    vertex_data = numpy.round(vertex_data, 1)
+
+                    vertex_data = vertex_data[:, [0, 2]]  # Drop the Y components to project to 2D.
+
+                    # Grab the set of unique points.
+                    #
+                    # This basically finds the unique rows in the array by treating them as opaque groups of bytes
+                    # which are as long as the 2 float64s in each row, and giving this view to numpy.unique() to munch.
+                    # See http://stackoverflow.com/questions/16970982/find-unique-rows-in-numpy-array
+                    vertex_byte_view = numpy.ascontiguousarray(vertex_data).view(
+                        numpy.dtype((numpy.void, vertex_data.dtype.itemsize * vertex_data.shape[1])))
+                    _, idx = numpy.unique(vertex_byte_view, return_index=True)
+                    vertex_data = vertex_data[idx]  # Select the unique rows by index.
+
+                    hull = Polygon(vertex_data)
+
+                    if len(vertex_data) >= 4:
+                        # First, calculate the normal convex hull around the points
+                        convex_hull = hull.getConvexHull()
+
+                        # Then, do a Minkowski hull with a simple 1x1 quad to outset and round the normal convex hull.
+                        # This is done because of rounding errors.
+                        rounded_hull = convex_hull.getMinkowskiHull(Polygon(numpy.array([[-0.5, -0.5], [-0.5, 0.5], [0.5, 0.5], [0.5, -0.5]], numpy.float32)))
+
+            # Store the result in the cache
+            self._2d_convex_hull_mesh = mesh
+            self._2d_convex_hull_mesh_world_transform = world_transform
+            self._2d_convex_hull_mesh_result = rounded_hull
+
+            return rounded_hull
+
+    def _getHeadAndFans(self):
+        return Polygon(numpy.array(self._global_stack.getProperty("machine_head_with_fans_polygon"), numpy.float32))
+
+    def _compute2DConvexHeadFull(self):
+        return self._compute2DConvexHull().getMinkowskiHull(self._getHeadAndFans())
+
+    def _compute2DConvexHeadMin(self):
+        headAndFans = self._getHeadAndFans()
+        mirrored = headAndFans.mirror([0, 0], [0, 1]).mirror([0, 0], [1, 0])  # Mirror horizontally & vertically.
+        head_and_fans = self._getHeadAndFans().intersectionConvexHulls(mirrored)
+
+        # Min head hull is used for the push free
+        min_head_hull = self._compute2DConvexHull().getMinkowskiHull(head_and_fans)
+        return min_head_hull
+
+    def _roundHull(self, convex_hull):
+        return convex_hull.getMinkowskiHull(Polygon(numpy.array([[-0.5, -0.5], [-0.5, 0.5], [0.5, 0.5], [0.5, -0.5]], numpy.float32)))
+
+    def _onChanged(self, *args):
+        self.recomputeConvexHull()
 
     def _onGlobalStackChanged(self):
         if self._global_stack:
@@ -124,3 +225,11 @@ class ConvexHullDecorator(SceneNodeDecorator):
             self._global_stack.containersChanged.connect(self._onChanged)
 
             self._onChanged()
+
+    ## Returns true if node is a descendent or the same as the root node.
+    def __isDescendant(self, root, node):
+        if node is None:
+            return False
+        if root is node:
+            return True
+        return self.__isDescendant(root, node.getParent())
diff --git a/cura/ConvexHullJob.py b/cura/ConvexHullJob.py
deleted file mode 100644
index 449b233b93..0000000000
--- a/cura/ConvexHullJob.py
+++ /dev/null
@@ -1,110 +0,0 @@
-# Copyright (c) 2015 Ultimaker B.V.
-# Cura is released under the terms of the AGPLv3 or higher.
-
-from UM.Job import Job
-from UM.Application import Application
-from UM.Math.Polygon import Polygon
-
-import numpy
-import copy
-from . import ConvexHullNode
-
-##  Job to async calculate the convex hull of a node.
-class ConvexHullJob(Job):
-    def __init__(self, node):
-        super().__init__()
-
-        self._node = node
-
-    def run(self):
-        if not self._node:
-            return
-        ## If the scene node is a group, use the hull of the children to calculate its hull.
-        if self._node.callDecoration("isGroup"):
-            hull = Polygon(numpy.zeros((0, 2), dtype=numpy.int32))
-            for child in self._node.getChildren():
-                child_hull = child.callDecoration("getConvexHull") 
-                if child_hull:
-                    hull.setPoints(numpy.append(hull.getPoints(), child_hull.getPoints(), axis = 0))
-
-                if hull.getPoints().size < 3:
-                    self._node.callDecoration("setConvexHull", None)
-                    self._node.callDecoration("setConvexHullJob", None)
-                    return
-
-                Job.yieldThread()
-
-        else: 
-            if not self._node.getMeshData():
-                return
-            mesh = self._node.getMeshData()
-            vertex_data = mesh.getTransformed(self._node.getWorldTransformation()).getVertices()
-            # Don't use data below 0.
-            # TODO; We need a better check for this as this gives poor results for meshes with long edges.
-            vertex_data = vertex_data[vertex_data[:,1] >= 0]
-
-            # Round the vertex data to 1/10th of a mm, then remove all duplicate vertices
-            # This is done to greatly speed up further convex hull calculations as the convex hull
-            # becomes much less complex when dealing with highly detailed models.
-            vertex_data = numpy.round(vertex_data, 1)
-
-            vertex_data = vertex_data[:, [0, 2]]    # Drop the Y components to project to 2D.
-
-            # Grab the set of unique points.
-            #
-            # This basically finds the unique rows in the array by treating them as opaque groups of bytes
-            # which are as long as the 2 float64s in each row, and giving this view to numpy.unique() to munch.
-            # See http://stackoverflow.com/questions/16970982/find-unique-rows-in-numpy-array
-            vertex_byte_view = numpy.ascontiguousarray(vertex_data).view(numpy.dtype((numpy.void, vertex_data.dtype.itemsize * vertex_data.shape[1])))
-            _, idx = numpy.unique(vertex_byte_view, return_index=True)
-            vertex_data = vertex_data[idx]  # Select the unique rows by index.
-
-            hull = Polygon(vertex_data)
-
-        # First, calculate the normal convex hull around the points
-        hull = hull.getConvexHull()
-
-        # Then, do a Minkowski hull with a simple 1x1 quad to outset and round the normal convex hull.
-        # This is done because of rounding errors.
-        hull = hull.getMinkowskiHull(Polygon(numpy.array([[-0.5, -0.5], [-0.5, 0.5], [0.5, 0.5], [0.5, -0.5]], numpy.float32)))
-
-        global_stack = Application.getInstance().getGlobalContainerStack()
-        if global_stack:
-            if global_stack.getProperty("print_sequence", "value")== "one_at_a_time" and not self._node.getParent().callDecoration("isGroup"):
-                # Printing one at a time and it's not an object in a group
-                self._node.callDecoration("setConvexHullBoundary", copy.deepcopy(hull))
-                head_and_fans = Polygon(numpy.array(global_stack.getProperty("machine_head_with_fans_polygon", "value"), numpy.float32))
-
-                # Full head hull is used to actually check the order.
-                full_head_hull = hull.getMinkowskiHull(head_and_fans)
-                self._node.callDecoration("setConvexHullHeadFull", full_head_hull)
-                mirrored = copy.deepcopy(head_and_fans)
-                mirrored.mirror([0, 0], [0, 1]) #Mirror horizontally.
-                mirrored.mirror([0, 0], [1, 0]) #Mirror vertically.
-                head_and_fans = head_and_fans.intersectionConvexHulls(mirrored)
-
-                # Min head hull is used for the push free
-                min_head_hull = hull.getMinkowskiHull(head_and_fans)
-                self._node.callDecoration("setConvexHullHead", min_head_hull)
-                hull = hull.getMinkowskiHull(Polygon(numpy.array(global_stack.getProperty("machine_head_polygon","value"),numpy.float32)))
-            else:
-                self._node.callDecoration("setConvexHullHead", None)
-        if self._node.getParent() is None:  # Node was already deleted before job is done.
-            self._node.callDecoration("setConvexHullNode",None)
-            self._node.callDecoration("setConvexHull", None)
-            self._node.callDecoration("setConvexHullJob", None)
-            return
-
-        hull_node = ConvexHullNode.ConvexHullNode(self._node, hull, Application.getInstance().getController().getScene().getRoot())
-        self._node.callDecoration("setConvexHullNode", hull_node)
-        self._node.callDecoration("setConvexHull", hull)
-        self._node.callDecoration("setConvexHullJob", None)
-
-        if self._node.getParent() and self._node.getParent().callDecoration("isGroup"):
-            job = self._node.getParent().callDecoration("getConvexHullJob")
-            if job:
-                job.cancel()
-            self._node.getParent().callDecoration("setConvexHull", None)
-            hull_node = self._node.getParent().callDecoration("getConvexHullNode")
-            if hull_node:
-                hull_node.setParent(None)
diff --git a/cura/ConvexHullNode.py b/cura/ConvexHullNode.py
index 905aeb16d4..be571d111e 100644
--- a/cura/ConvexHullNode.py
+++ b/cura/ConvexHullNode.py
@@ -9,7 +9,6 @@ from UM.Mesh.MeshBuilder import MeshBuilder  # To create a mesh to display the c
 
 from UM.View.GL.OpenGL import OpenGL
 
-
 class ConvexHullNode(SceneNode):
     ##  Convex hull node is a special type of scene node that is used to display a 2D area, to indicate the
     #   location an object uses on the buildplate. This area (or area's in case of one at a time printing) is
@@ -31,21 +30,23 @@ class ConvexHullNode(SceneNode):
 
         # The node this mesh is "watching"
         self._node = node
-        self._node.transformationChanged.connect(self._onNodePositionChanged)
-        self._node.parentChanged.connect(self._onNodeParentChanged)
         self._node.decoratorsChanged.connect(self._onNodeDecoratorsChanged)
         self._onNodeDecoratorsChanged(self._node)
 
         self._convex_hull_head_mesh = None
         self._hull = hull
 
-        hull_mesh = self.createHullMesh(self._hull.getPoints())
-        if hull_mesh:
-            self.setMeshData(hull_mesh)
+        if self._hull:
+            hull_mesh = self.createHullMesh(self._hull.getPoints())
+            if hull_mesh:
+                self.setMeshData(hull_mesh)
         convex_hull_head = self._node.callDecoration("getConvexHullHead")
         if convex_hull_head:
             self._convex_hull_head_mesh = self.createHullMesh(convex_hull_head.getPoints())
 
+    def getHull(self):
+        return self._hull
+
     ##  Actually create the mesh from the hullpoints
     #   /param hull_points list of xy values
     #   /return meshData
@@ -62,7 +63,7 @@ class ConvexHullNode(SceneNode):
             mesh_builder.addFace(point_first, point_previous, point_new, color = self._color)
             point_previous = point_new  # Prepare point_previous for the next triangle.
 
-        return mesh_builder.getData()
+        return mesh_builder.build()
 
     def getWatchedNode(self):
         return self._node
@@ -73,24 +74,13 @@ class ConvexHullNode(SceneNode):
             self._shader.setUniformValue("u_color", self._color)
 
         if self.getParent():
-            renderer.queueNode(self, transparent = True, shader = self._shader, backface_cull = True, sort = -8)
-            if self._convex_hull_head_mesh:
-                renderer.queueNode(self, shader = self._shader, transparent = True, mesh = self._convex_hull_head_mesh, backface_cull = True, sort = -8)
+            if self.getMeshData():
+                renderer.queueNode(self, transparent = True, shader = self._shader, backface_cull = True, sort = -8)
+                if self._convex_hull_head_mesh:
+                    renderer.queueNode(self, shader = self._shader, transparent = True, mesh = self._convex_hull_head_mesh, backface_cull = True, sort = -8)
 
         return True
 
-    def _onNodePositionChanged(self, node):
-        if node.callDecoration("getConvexHull"): 
-            node.callDecoration("setConvexHull", None)
-            node.callDecoration("setConvexHullNode", None)
-            self.setParent(None)  # Garbage collection should delete this node after a while.
-
-    def _onNodeParentChanged(self, node):
-        if node.getParent():
-            self.setParent(self._original_parent)
-        else:
-            self.setParent(None)
-
     def _onNodeDecoratorsChanged(self, node):
         self._color = Color(35, 35, 35, 0.5)
 
diff --git a/cura/CuraApplication.py b/cura/CuraApplication.py
index 5f5880e3d5..12818e1e87 100644
--- a/cura/CuraApplication.py
+++ b/cura/CuraApplication.py
@@ -49,7 +49,6 @@ from PyQt5.QtCore import pyqtSlot, QUrl, pyqtSignal, pyqtProperty, QEvent, Q_ENU
 from PyQt5.QtGui import QColor, QIcon
 from PyQt5.QtQml import qmlRegisterUncreatableType, qmlRegisterSingletonType, qmlRegisterType
 
-import ast #For literal eval of extruder setting types.
 import platform
 import sys
 import os.path
@@ -122,7 +121,8 @@ class CuraApplication(QtApplication):
         self._i18n_catalog = None
         self._previous_active_tool = None
         self._platform_activity = False
-        self._scene_bounding_box = AxisAlignedBox()
+        self._scene_bounding_box = AxisAlignedBox.Null
+
         self._job_name = None
         self._center_after_select = False
         self._camera_animation = None
@@ -362,7 +362,8 @@ class CuraApplication(QtApplication):
 
         self.showSplashMessage(self._i18n_catalog.i18nc("@info:progress", "Loading interface..."))
 
-        ExtruderManager.ExtruderManager.getInstance() #Initialise extruder so as to listen to global container stack changes before the first global container stack is set.
+        # Initialise extruder so as to listen to global container stack changes before the first global container stack is set.
+        ExtruderManager.ExtruderManager.getInstance()
         qmlRegisterSingletonType(MachineManagerModel.MachineManagerModel, "Cura", 1, 0, "MachineManager",
                                  MachineManagerModel.createMachineManagerModel)
 
@@ -468,12 +469,14 @@ class CuraApplication(QtApplication):
 
             count += 1
             if not scene_bounding_box:
-                scene_bounding_box = copy.deepcopy(node.getBoundingBox())
+                scene_bounding_box = node.getBoundingBox()
             else:
-                scene_bounding_box += node.getBoundingBox()
+                other_bb = node.getBoundingBox()
+                if other_bb is not None:
+                    scene_bounding_box = scene_bounding_box + node.getBoundingBox()
 
         if not scene_bounding_box:
-            scene_bounding_box = AxisAlignedBox()
+            scene_bounding_box = AxisAlignedBox.Null
 
         if repr(self._scene_bounding_box) != repr(scene_bounding_box):
             self._scene_bounding_box = scene_bounding_box
@@ -738,7 +741,6 @@ class CuraApplication(QtApplication):
 
                     # Add all individual nodes to the selection
                     Selection.add(child)
-                    child.callDecoration("setConvexHull", None)
 
                 op.push()
                 # Note: The group removes itself from the scene once all its children have left it,
diff --git a/cura/Layer.py b/cura/Layer.py
index a95fbf64ef..904e5528a3 100644
--- a/cura/Layer.py
+++ b/cura/Layer.py
@@ -96,4 +96,4 @@ class Layer:
 
                 builder.addQuad(point1, point2, point3, point4, color = poly_color)
 
-        return builder.getData()
\ No newline at end of file
+        return builder.build()
diff --git a/cura/LayerData.py b/cura/LayerData.py
index 4aa7d1f4d4..ad5326373e 100644
--- a/cura/LayerData.py
+++ b/cura/LayerData.py
@@ -1,66 +1,25 @@
 # Copyright (c) 2015 Ultimaker B.V.
 # Cura is released under the terms of the AGPLv3 or higher.
-from .Layer import Layer
-from .LayerPolygon import LayerPolygon
 from UM.Mesh.MeshData import MeshData
 
-import numpy
-
-
+##  Class to holds the layer mesh and information about the layers.
+# Immutable, use LayerDataBuilder to create one of these.
 class LayerData(MeshData):
-    def __init__(self):
-        super().__init__()
-        self._layers = {}
-        self._element_counts = {}
-
-    def addLayer(self, layer):
-        if layer not in self._layers:
-            self._layers[layer] = Layer(layer)
-
-    def addPolygon(self, layer, polygon_type, data, line_width):
-        if layer not in self._layers:
-            self.addLayer(layer)
-
-        p = LayerPolygon(self, polygon_type, data, line_width)
-        self._layers[layer].polygons.append(p)
+    def __init__(self, vertices = None, normals = None, indices = None, colors = None, uvs = None, file_name = None,
+        center_position = None, layers=None, element_counts=None):
+        super().__init__(vertices=vertices, normals=normals, indices=indices, colors=colors, uvs=uvs,
+                         file_name=file_name, center_position=center_position)
+        self._layers = layers
+        self._element_counts = element_counts
 
     def getLayer(self, layer):
         if layer in self._layers:
             return self._layers[layer]
+        else:
+            return None
 
     def getLayers(self):
         return self._layers
 
     def getElementCounts(self):
         return self._element_counts
-
-    def setLayerHeight(self, layer, height):
-        if layer not in self._layers:
-            self.addLayer(layer)
-
-        self._layers[layer].setHeight(height)
-
-    def setLayerThickness(self, layer, thickness):
-        if layer not in self._layers:
-            self.addLayer(layer)
-
-        self._layers[layer].setThickness(thickness)
-
-    def build(self):
-        vertex_count = 0
-        for layer, data in self._layers.items():
-            vertex_count += data.vertexCount()
-
-        vertices = numpy.empty((vertex_count, 3), numpy.float32)
-        colors = numpy.empty((vertex_count, 4), numpy.float32)
-        indices = numpy.empty((vertex_count, 2), numpy.int32)
-
-        offset = 0
-        for layer, data in self._layers.items():
-            offset = data.build(offset, vertices, colors, indices)
-            self._element_counts[layer] = data.elementCount
-
-        self.clear()
-        self.addVertices(vertices)
-        self.addColors(colors)
-        self.addIndices(indices.flatten())
diff --git a/cura/LayerDataBuilder.py b/cura/LayerDataBuilder.py
new file mode 100644
index 0000000000..7e8e0e636b
--- /dev/null
+++ b/cura/LayerDataBuilder.py
@@ -0,0 +1,72 @@
+# Copyright (c) 2015 Ultimaker B.V.
+# Cura is released under the terms of the AGPLv3 or higher.
+
+from .Layer import Layer
+from .LayerPolygon import LayerPolygon
+from UM.Mesh.MeshBuilder import MeshBuilder
+from .LayerData import LayerData
+
+import numpy
+
+## Builder class for constructing a LayerData object
+class LayerDataBuilder(MeshBuilder):
+    def __init__(self):
+        super().__init__()
+        self._layers = {}
+        self._element_counts = {}
+
+    def addLayer(self, layer):
+        if layer not in self._layers:
+            self._layers[layer] = Layer(layer)
+
+    def addPolygon(self, layer, polygon_type, data, line_width):
+        if layer not in self._layers:
+            self.addLayer(layer)
+
+        p = LayerPolygon(self, polygon_type, data, line_width)
+        self._layers[layer].polygons.append(p)
+
+    def getLayer(self, layer):
+        if layer in self._layers:
+            return self._layers[layer]
+
+    def getLayers(self):
+        return self._layers
+
+    def getElementCounts(self):
+        return self._element_counts
+
+    def setLayerHeight(self, layer, height):
+        if layer not in self._layers:
+            self.addLayer(layer)
+
+        self._layers[layer].setHeight(height)
+
+    def setLayerThickness(self, layer, thickness):
+        if layer not in self._layers:
+            self.addLayer(layer)
+
+        self._layers[layer].setThickness(thickness)
+
+    def build(self):
+        vertex_count = 0
+        for layer, data in self._layers.items():
+            vertex_count += data.vertexCount()
+
+        vertices = numpy.empty((vertex_count, 3), numpy.float32)
+        colors = numpy.empty((vertex_count, 4), numpy.float32)
+        indices = numpy.empty((vertex_count, 2), numpy.int32)
+
+        offset = 0
+        for layer, data in self._layers.items():
+            offset = data.build(offset, vertices, colors, indices)
+            self._element_counts[layer] = data.elementCount
+
+        self.addVertices(vertices)
+        self.addColors(colors)
+        self.addIndices(indices.flatten())
+
+        return LayerData(vertices=self.getVertices(), normals=self.getNormals(), indices=self.getIndices(),
+                        colors=self.getColors(), uvs=self.getUVCoordinates(), file_name=self.getFileName(),
+                        center_position=self.getCenterPosition(), layers=self._layers,
+                        element_counts=self._element_counts)
diff --git a/cura/PlatformPhysics.py b/cura/PlatformPhysics.py
index 78f2b4938b..c43d0d09d7 100644
--- a/cura/PlatformPhysics.py
+++ b/cura/PlatformPhysics.py
@@ -14,7 +14,6 @@ from UM.Preferences import Preferences
 from cura.ConvexHullDecorator import ConvexHullDecorator
 
 from . import PlatformPhysicsOperation
-from . import ConvexHullJob
 from . import ZOffsetDecorator
 
 import copy
@@ -27,7 +26,6 @@ class PlatformPhysics:
         self._controller.toolOperationStarted.connect(self._onToolOperationStarted)
         self._controller.toolOperationStopped.connect(self._onToolOperationStopped)
         self._build_volume = volume
-
         self._enabled = True
 
         self._change_timer = QTimer()
@@ -46,16 +44,13 @@ class PlatformPhysics:
 
         root = self._controller.getScene().getRoot()
         for node in BreadthFirstIterator(root):
-            if node is root or type(node) is not SceneNode:
+            if node is root or type(node) is not SceneNode or node.getBoundingBox() is None:
                 continue
 
             bbox = node.getBoundingBox()
-            if not bbox or not bbox.isValid():
-                self._change_timer.start()
-                continue
 
-            build_volume_bounding_box = copy.deepcopy(self._build_volume.getBoundingBox())
-            build_volume_bounding_box.setBottom(-9001) # Ignore intersections with the bottom
+            # Ignore intersections with the bottom
+            build_volume_bounding_box = self._build_volume.getBoundingBox().set(bottom=-9001)
             node._outside_buildarea = False
 
             # Mark the node as outside the build volume if the bounding box test fails.
@@ -67,9 +62,9 @@ class PlatformPhysics:
             if not (node.getParent() and node.getParent().callDecoration("isGroup")): #If an object is grouped, don't move it down
                 z_offset = node.callDecoration("getZOffset") if node.getDecorator(ZOffsetDecorator.ZOffsetDecorator) else 0
                 if bbox.bottom > 0:
-                    move_vector.setY(-bbox.bottom + z_offset)
+                    move_vector = move_vector.set(y=-bbox.bottom + z_offset)
                 elif bbox.bottom < z_offset:
-                    move_vector.setY((-bbox.bottom) - z_offset)
+                    move_vector = move_vector.set(y=(-bbox.bottom) - z_offset)
 
             #if not Float.fuzzyCompare(bbox.bottom, 0.0):
             #   pass#move_vector.setY(-bbox.bottom)
@@ -77,14 +72,9 @@ class PlatformPhysics:
             # If there is no convex hull for the node, start calculating it and continue.
             if not node.getDecorator(ConvexHullDecorator):
                 node.addDecorator(ConvexHullDecorator())
-            
-            if not node.callDecoration("getConvexHull"):
-                if not node.callDecoration("getConvexHullJob"):
-                    job = ConvexHullJob.ConvexHullJob(node)
-                    job.start()
-                    node.callDecoration("setConvexHullJob", job)
-                    
-            elif Preferences.getInstance().getValue("physics/automatic_push_free"):
+            node.callDecoration("recomputeConvexHull")
+
+            if Preferences.getInstance().getValue("physics/automatic_push_free"):
                 # Check for collisions between convex hulls
                 for other_node in BreadthFirstIterator(root):
                     # Ignore root, ourselves and anything that is not a normal SceneNode.
@@ -125,8 +115,7 @@ class PlatformPhysics:
 
                     if overlap is None:
                         continue
-                    move_vector.setX(overlap[0] * 1.1)
-                    move_vector.setZ(overlap[1] * 1.1)
+                    move_vector = move_vector.set(x=overlap[0] * 1.1, z=overlap[1] * 1.1)
             convex_hull = node.callDecoration("getConvexHull")
             if convex_hull:
                 if not convex_hull.isValid():
@@ -139,7 +128,7 @@ class PlatformPhysics:
 
                     node._outside_buildarea = True
 
-            if move_vector != Vector():
+            if not Vector.Null.equals(move_vector, epsilon=1e-5):
                 op = PlatformPhysicsOperation.PlatformPhysicsOperation(node, move_vector)
                 op.push()
 
diff --git a/cura/PlatformPhysicsOperation.py b/cura/PlatformPhysicsOperation.py
index 5d2089e8af..fa58e45d9c 100644
--- a/cura/PlatformPhysicsOperation.py
+++ b/cura/PlatformPhysicsOperation.py
@@ -28,4 +28,4 @@ class PlatformPhysicsOperation(Operation):
         return group
 
     def __repr__(self):
-        return "PlatformPhysicsOperation(t = {0})".format(self._position)
+        return "PlatformPhysicsOperation(new_position = {0})".format(self._new_position)
diff --git a/plugins/CuraEngineBackend/ProcessSlicedLayersJob.py b/plugins/CuraEngineBackend/ProcessSlicedLayersJob.py
index 46b2d24bc5..d23f71e874 100644
--- a/plugins/CuraEngineBackend/ProcessSlicedLayersJob.py
+++ b/plugins/CuraEngineBackend/ProcessSlicedLayersJob.py
@@ -12,7 +12,7 @@ from UM.i18n import i18nCatalog
 
 from UM.Math.Vector import Vector
 
-from cura import LayerData
+from cura import LayerDataBuilder
 from cura import LayerDataDecorator
 
 import numpy
@@ -63,7 +63,7 @@ class ProcessSlicedLayersJob(Job):
                 return
 
         mesh = MeshData()
-        layer_data = LayerData.LayerData()
+        layer_data = LayerDataBuilder.LayerDataBuilder()
         layer_count = len(self._layers)
 
         # Find the minimum layer number
@@ -115,7 +115,7 @@ class ProcessSlicedLayersJob(Job):
                 self._progress.setProgress(progress)
 
         # We are done processing all the layers we got from the engine, now create a mesh out of the data
-        layer_data.build()
+        layer_mesh = layer_data.build()
 
         if self._abort_requested:
             if self._progress:
@@ -124,7 +124,7 @@ class ProcessSlicedLayersJob(Job):
 
         # Add LayerDataDecorator to scene node to indicate that the node has layer data
         decorator = LayerDataDecorator.LayerDataDecorator()
-        decorator.setLayerData(layer_data)
+        decorator.setLayerData(layer_mesh)
         new_node.addDecorator(decorator)
 
         new_node.setMeshData(mesh)
diff --git a/plugins/ImageReader/ImageReader.py b/plugins/ImageReader/ImageReader.py
index 0d6c12b13d..9d70dde8e1 100644
--- a/plugins/ImageReader/ImageReader.py
+++ b/plugins/ImageReader/ImageReader.py
@@ -7,7 +7,7 @@ from PyQt5.QtGui import QImage, qRed, qGreen, qBlue
 from PyQt5.QtCore import Qt
 
 from UM.Mesh.MeshReader import MeshReader
-from UM.Mesh.MeshData import MeshData
+from UM.Mesh.MeshBuilder import MeshBuilder
 from UM.Scene.SceneNode import SceneNode
 from UM.Math.Vector import Vector
 from UM.Job import Job
@@ -48,13 +48,9 @@ class ImageReader(MeshReader):
         return self._generateSceneNode(file_name, size, self._ui.peak_height, self._ui.base_height, self._ui.smoothing, 512, self._ui.image_color_invert)
 
     def _generateSceneNode(self, file_name, xz_size, peak_height, base_height, blur_iterations, max_size, image_color_invert):
-        mesh = None # TODO: @UnusedVariable
-        scene_node = None # TODO: @UnusedVariable
-
         scene_node = SceneNode()
 
-        mesh = MeshData()
-        scene_node.setMeshData(mesh)
+        mesh = MeshBuilder()
 
         img = QImage(file_name)
 
@@ -76,9 +72,9 @@ class ImageReader(MeshReader):
         scale_vector = Vector(xz_size, peak_height, xz_size)
 
         if width > height:
-            scale_vector.setZ(scale_vector.z * aspect)
+            scale_vector = scale_vector.set(z=scale_vector.z * aspect)
         elif height > width:
-            scale_vector.setX(scale_vector.x / aspect)
+            scale_vector = scale_vector.set(x=scale_vector.x / aspect)
 
         if width > max_size or height > max_size:
             scale_factor = max_size / width
@@ -173,8 +169,8 @@ class ImageReader(MeshReader):
         geo_height = height_minus_one * texel_height
 
         # bottom
-        mesh.addFace(0, 0, 0, 0, 0, geo_height, geo_width, 0, geo_height)
-        mesh.addFace(geo_width, 0, geo_height, geo_width, 0, 0, 0, 0, 0)
+        mesh.addFaceByPoints(0, 0, 0, 0, 0, geo_height, geo_width, 0, geo_height)
+        mesh.addFaceByPoints(geo_width, 0, geo_height, geo_width, 0, 0, 0, 0, 0)
 
         # north and south walls
         for n in range(0, width_minus_one):
@@ -187,11 +183,11 @@ class ImageReader(MeshReader):
             hs0 = height_data[height_minus_one, n]
             hs1 = height_data[height_minus_one, n + 1]
 
-            mesh.addFace(x, 0, 0, nx, 0, 0, nx, hn1, 0)
-            mesh.addFace(nx, hn1, 0, x, hn0, 0, x, 0, 0)
+            mesh.addFaceByPoints(x, 0, 0, nx, 0, 0, nx, hn1, 0)
+            mesh.addFaceByPoints(nx, hn1, 0, x, hn0, 0, x, 0, 0)
 
-            mesh.addFace(x, 0, geo_height, nx, 0, geo_height, nx, hs1, geo_height)
-            mesh.addFace(nx, hs1, geo_height, x, hs0, geo_height, x, 0, geo_height)
+            mesh.addFaceByPoints(x, 0, geo_height, nx, 0, geo_height, nx, hs1, geo_height)
+            mesh.addFaceByPoints(nx, hs1, geo_height, x, hs0, geo_height, x, 0, geo_height)
 
         # west and east walls
         for n in range(0, height_minus_one):
@@ -204,12 +200,14 @@ class ImageReader(MeshReader):
             he0 = height_data[n, width_minus_one]
             he1 = height_data[n + 1, width_minus_one]
 
-            mesh.addFace(0, 0, y, 0, 0, ny, 0, hw1, ny)
-            mesh.addFace(0, hw1, ny, 0, hw0, y, 0, 0, y)
+            mesh.addFaceByPoints(0, 0, y, 0, 0, ny, 0, hw1, ny)
+            mesh.addFaceByPoints(0, hw1, ny, 0, hw0, y, 0, 0, y)
 
-            mesh.addFace(geo_width, 0, y, geo_width, 0, ny, geo_width, he1, ny)
-            mesh.addFace(geo_width, he1, ny, geo_width, he0, y, geo_width, 0, y)
+            mesh.addFaceByPoints(geo_width, 0, y, geo_width, 0, ny, geo_width, he1, ny)
+            mesh.addFaceByPoints(geo_width, he1, ny, geo_width, he0, y, geo_width, 0, y)
 
         mesh.calculateNormals(fast=True)
 
+        scene_node.setMeshData(mesh.build())
+
         return scene_node
diff --git a/plugins/LayerView/LayerView.py b/plugins/LayerView/LayerView.py
index 50ab7f968e..cd7a17a357 100644
--- a/plugins/LayerView/LayerView.py
+++ b/plugins/LayerView/LayerView.py
@@ -8,7 +8,7 @@ from UM.Event import Event, KeyEvent
 from UM.Signal import Signal
 from UM.Scene.Selection import Selection
 from UM.Math.Color import Color
-from UM.Mesh.MeshData import MeshData
+from UM.Mesh.MeshBuilder import MeshBuilder
 from UM.Job import Job
 from UM.Preferences import Preferences
 
@@ -240,7 +240,7 @@ class _CreateTopLayersJob(Job):
         if self._cancel or not layer_data:
             return
 
-        layer_mesh = MeshData()
+        layer_mesh = MeshBuilder()
         for i in range(self._solid_layers):
             layer_number = self._layer_number - i
             if layer_number < 0:
@@ -275,7 +275,7 @@ class _CreateTopLayersJob(Job):
         if not jump_mesh or jump_mesh.getVertices() is None:
             jump_mesh = None
 
-        self.setResult({ "layers": layer_mesh, "jumps": jump_mesh })
+        self.setResult({ "layers": layer_mesh.build(), "jumps": jump_mesh })
 
     def cancel(self):
         self._cancel = True