Cura/plugins/AMFReader/AMFReader.py

# Copyright (c) 2019 fieldOfView, Ultimaker B.V.
# Cura is released under the terms of the LGPLv3 or higher.

# This AMF parser is based on the AMF parser in legacy cura:
# https://github.com/daid/LegacyCura/blob/ad7641e059048c7dcb25da1f47c0a7e95e7f4f7c/Cura/util/meshLoaders/amf.py
from UM.MimeTypeDatabase import MimeTypeDatabase, MimeType
from cura.CuraApplication import CuraApplication
from UM.Logger import Logger

from UM.Mesh.MeshData import MeshData, calculateNormalsFromIndexedVertices
from UM.Mesh.MeshReader import MeshReader

from cura.Scene.CuraSceneNode import CuraSceneNode
from cura.Scene.SliceableObjectDecorator import SliceableObjectDecorator
from cura.Scene.BuildPlateDecorator import BuildPlateDecorator
from cura.Scene.ConvexHullDecorator import ConvexHullDecorator
from UM.Scene.GroupDecorator import GroupDecorator

import numpy
import trimesh
import os.path
import zipfile

MYPY = False
try:
    if not MYPY:
        import xml.etree.cElementTree as ET
except ImportError:
    import xml.etree.ElementTree as ET

from typing import Dict


class AMFReader(MeshReader):
    def __init__(self) -> None:
        super().__init__()
        self._supported_extensions = [".amf"]
        self._namespaces = {}   # type: Dict[str, str]

        MimeTypeDatabase.addMimeType(
            MimeType(
                name = "application/x-amf",
                comment = "AMF",
                suffixes = ["amf"]
            )
        )

    # Main entry point
    # Reads the file, returns a SceneNode (possibly with nested ones), or None
    def _read(self, file_name):
        base_name = os.path.basename(file_name)
        try:
            zipped_file = zipfile.ZipFile(file_name)
            xml_document = zipped_file.read(zipped_file.namelist()[0])
            zipped_file.close()
        except zipfile.BadZipfile:
            raw_file = open(file_name, "r")
            xml_document = raw_file.read()
            raw_file.close()

        try:
            amf_document = ET.fromstring(xml_document)
        except ET.ParseError:
            Logger.log("e", "Could not parse XML in file %s" % base_name)
            return None

        if "unit" in amf_document.attrib:
            unit = amf_document.attrib["unit"].lower()
        else:
            unit = "millimeter"
        if unit == "millimeter":
            scale = 1.0
        elif unit == "meter":
            scale = 1000.0
        elif unit == "inch":
            scale = 25.4
        elif unit == "feet":
            scale = 304.8
        elif unit == "micron":
            scale = 0.001
        else:
            Logger.log("w", "Unknown unit in amf: %s. Using mm instead." % unit)
            scale = 1.0

        nodes = []
        for amf_object in amf_document.iter("object"):
            for amf_mesh in amf_object.iter("mesh"):
                amf_mesh_vertices = []
                for vertices in amf_mesh.iter("vertices"):
                    for vertex in vertices.iter("vertex"):
                        for coordinates in vertex.iter("coordinates"):
                            v = [0.0, 0.0, 0.0]
                            for t in coordinates:
                                if t.tag == "x":
                                    v[0] = float(t.text) * scale
                                elif t.tag == "y":
                                    v[2] = -float(t.text) * scale
                                elif t.tag == "z":
                                    v[1] = float(t.text) * scale
                            amf_mesh_vertices.append(v)
                if not amf_mesh_vertices:
                    continue

                indices = []
                for volume in amf_mesh.iter("volume"):
                    for triangle in volume.iter("triangle"):
                        f = [0, 0, 0]
                        for t in triangle:
                            if t.tag == "v1":
                                f[0] = int(t.text)
                            elif t.tag == "v2":
                                f[1] = int(t.text)
                            elif t.tag == "v3":
                                f[2] = int(t.text)
                        indices.append(f)

                    mesh = trimesh.base.Trimesh(vertices = numpy.array(amf_mesh_vertices, dtype = numpy.float32), faces = numpy.array(indices, dtype = numpy.int32))
                    mesh.merge_vertices()
                    mesh.remove_unreferenced_vertices()
                    mesh.fix_normals()
                    mesh_data = self._toMeshData(mesh)

                    new_node = CuraSceneNode()
                    new_node.setSelectable(True)
                    new_node.setMeshData(mesh_data)
                    new_node.setName(base_name if len(nodes) == 0 else "%s %d" % (base_name, len(nodes)))
                    new_node.addDecorator(BuildPlateDecorator(CuraApplication.getInstance().getMultiBuildPlateModel().activeBuildPlate))
                    new_node.addDecorator(SliceableObjectDecorator())

                    nodes.append(new_node)

        if not nodes:
            Logger.log("e", "No meshes in file %s" % base_name)
            return None

        if len(nodes) == 1:
            return nodes[0]

        # Add all scenenodes to a group so they stay together
        group_node = CuraSceneNode()
        group_node.addDecorator(GroupDecorator())
        group_node.addDecorator(ConvexHullDecorator())
        group_node.addDecorator(BuildPlateDecorator(CuraApplication.getInstance().getMultiBuildPlateModel().activeBuildPlate))

        for node in nodes:
            node.setParent(group_node)

        return group_node

    def _toMeshData(self, tri_node: trimesh.base.Trimesh) -> MeshData:
        tri_faces = tri_node.faces
        tri_vertices = tri_node.vertices

        indices = []
        vertices = []

        index_count = 0
        face_count = 0
        for tri_face in tri_faces:
            face = []
            for tri_index in tri_face:
                vertices.append(tri_vertices[tri_index])
                face.append(index_count)
                index_count += 1
            indices.append(face)
            face_count += 1

        vertices = numpy.asarray(vertices, dtype = numpy.float32)
        indices = numpy.asarray(indices, dtype = numpy.int32)
        normals = calculateNormalsFromIndexedVertices(vertices, indices, face_count)

        mesh_data = MeshData(vertices = vertices, indices = indices, normals = normals)
        return mesh_data