Cura/cura/ConvexHullJob.py

# 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)