Merge pull request #2296 from mikedh/feat/3mfextra

Support 3MF component `path`

Author: mikedh

tests/test_3mf.py

@@ -60,7 +60,10 @@ def test_roundtrip(self):
             file_type="3mf",
         )
 
-        assert set(s.geometry.keys()) == set(r.geometry.keys())
+        assert set(s.geometry.keys()) == set(r.geometry.keys()), (
+            s.geometry.keys(),
+            r.geometry.keys(),
+        )
         assert g.np.allclose(s.bounds, r.bounds)
         assert g.np.isclose(s.area, r.area, rtol=1e-3)
 

trimesh/exchange/threemf.py

@@ -1,12 +1,35 @@
-import collections
 import io
 import uuid
 import zipfile
+from collections import defaultdict
 
 import numpy as np
 
 from .. import graph, util
 from ..constants import log
+from ..util import unique_name
+
+
+def _read_mesh(mesh):
+    vertices = mesh.find("{*}vertices")
+    v_array = np.array(
+        [
+            [i.attrib["x"], i.attrib["y"], i.attrib["z"]]
+            for i in vertices.iter("{*}vertex")
+        ],
+        dtype=np.float64,
+    )
+
+    faces = mesh.find("{*}triangles")
+    f_array = np.array(
+        [
+            [i.attrib["v1"], i.attrib["v2"], i.attrib["v3"]]
+            for i in faces.iter("{*}triangle")
+        ],
+        dtype=np.int64,
+    )
+
+    return v_array, f_array
 
 
 def load_3MF(file_obj, postprocess=True, **kwargs):
@@ -23,6 +46,7 @@ def load_3MF(file_obj, postprocess=True, **kwargs):
     kwargs : dict
       Constructor arguments for `trimesh.Scene`
     """
+
     # dict, {name in archive: BytesIo}
     archive = util.decompress(file_obj, file_type="zip")
     # get model with case-insensitive keys
@@ -40,66 +64,74 @@ def load_3MF(file_obj, postprocess=True, **kwargs):
     # { mesh id : mesh name}
     id_name = {}
     # { mesh id: (n,3) float vertices}
-    v_seq = {}
+    v_seq = defaultdict(list)
     # { mesh id: (n,3) int faces}
-    f_seq = {}
+    f_seq = defaultdict(list)
     # components are objects that contain other objects
     # {id : [other ids]}
-    components = collections.defaultdict(list)
+    components = defaultdict(list)
     # load information about the scene graph
     # each instance is a single geometry
     build_items = []
 
+    # keep track of names we can use
+    consumed_counts = {}
     consumed_names = set()
+
     # iterate the XML object and build elements with an LXML iterator
     # loaded elements are cleared to avoid ballooning memory
     model.seek(0)
-    for _, obj in etree.iterparse(model, tag=("{*}object", "{*}build")):
+    for _, obj in etree.iterparse(model, tag=("{*}object", "{*}build"), events=("end",)):
         # parse objects
         if "object" in obj.tag:
             # id is mandatory
             index = obj.attrib["id"]
 
             # start with stored name
-            name = obj.attrib.get("name", str(index))
             # apparently some exporters name multiple meshes
             # the same thing so check to see if it's been used
-            if name in consumed_names:
-                name = name + str(index)
+            name = unique_name(
+                obj.attrib.get("name", str(index)), consumed_names, consumed_counts
+            )
             consumed_names.add(name)
             # store name reference on the index
             id_name[index] = name
 
             # if the object has actual geometry data parse here
             for mesh in obj.iter("{*}mesh"):
-                vertices = mesh.find("{*}vertices")
-                v_seq[index] = np.array(
-                    [
-                        [i.attrib["x"], i.attrib["y"], i.attrib["z"]]
-                        for i in vertices.iter("{*}vertex")
-                    ],
-                    dtype=np.float64,
-                )
-                vertices.clear()
-                vertices.getparent().remove(vertices)
-
-                faces = mesh.find("{*}triangles")
-                f_seq[index] = np.array(
-                    [
-                        [i.attrib["v1"], i.attrib["v2"], i.attrib["v3"]]
-                        for i in faces.iter("{*}triangle")
-                    ],
-                    dtype=np.int64,
-                )
-                faces.clear()
-                faces.getparent().remove(faces)
+                v, f = _read_mesh(mesh)
+                v_seq[index].append(v)
+                f_seq[index].append(f)
 
             # components are references to other geometries
             for c in obj.iter("{*}component"):
                 mesh_index = c.attrib["objectid"]
                 transform = _attrib_to_transform(c.attrib)
                 components[index].append((mesh_index, transform))
 
+                # if this references another file as the `path` attrib
+                path = next(
+                    (v.strip("/") for k, v in c.attrib.items() if k.endswith("path")),
+                    None,
+                )
+                if path is not None and path in archive:
+                    archive[path].seek(0)
+                    name = unique_name(
+                        obj.attrib.get("name", str(mesh_index)),
+                        consumed_names,
+                        consumed_counts,
+                    )
+                    consumed_names.add(name)
+                    # store name reference on the index
+                    id_name[mesh_index] = name
+
+                    for _, m in etree.iterparse(
+                        archive[path], tag=("{*}mesh"), events=("end",)
+                    ):
+                        v, f = _read_mesh(m)
+                        v_seq[mesh_index].append(v)
+                        f_seq[mesh_index].append(f)
+
         # parse build
         if "build" in obj.tag:
             # scene graph information stored here, aka "build" the scene
@@ -109,19 +141,15 @@ def load_3MF(file_obj, postprocess=True, **kwargs):
                 # the index of the geometry this item instantiates
                 build_items.append((item.attrib["objectid"], transform))
 
-        # free resources
-        obj.clear()
-        obj.getparent().remove(obj)
-        del obj
-
     # have one mesh per 3MF object
     # one mesh per geometry ID, store as kwargs for the object
     meshes = {}
     for gid in v_seq.keys():
+        v, f = util.append_faces(v_seq[gid], f_seq[gid])
         name = id_name[gid]
         meshes[name] = {
-            "vertices": v_seq[gid],
-            "faces": f_seq[gid],
+            "vertices": v,
+            "faces": f,
             "metadata": metadata.copy(),
         }
         meshes[name].update(kwargs)
@@ -143,7 +171,7 @@ def load_3MF(file_obj, postprocess=True, **kwargs):
     # flatten the scene structure and simplify to
     # a single unique node per instance
     graph_args = []
-    parents = collections.defaultdict(set)
+    parents = defaultdict(set)
     for path in graph.multigraph_paths(G=g, source="world"):
         # collect all the transform on the path
         transforms = graph.multigraph_collect(G=g, traversal=path, attrib="matrix")
@@ -157,8 +185,9 @@ def load_3MF(file_obj, postprocess=True, **kwargs):
         last = path[-1][0]
         # if someone included an undefined component, skip it
         if last not in id_name:
-            log.debug(f"id {last} included but not defined!")
+            log.warning(f"id {last} included but not defined!")
             continue
+
         # frame names unique
         name = id_name[last] + util.unique_id()
         # index in meshes

trimesh/path/polygons.py

@@ -3,6 +3,7 @@
 from shapely.geometry import Polygon
 
 from .. import bounds, geometry, graph, grouping
+from ..boolean import reduce_cascade
 from ..constants import log
 from ..constants import tol_path as tol
 from ..transformations import transform_points
@@ -162,14 +163,14 @@ def edges_to_polygons(edges: NDArray[int64], vertices: NDArray[float64]):
     # find which polygons contain which other polygons
     roots, tree = enclosure_tree(polygons)
 
-    # generate list of polygons with proper interiors
-    complete = []
-    for root in roots:
-        interior = list(tree[root].keys())
-        shell = polygons[root].exterior.coords
-        holes = [polygons[i].exterior.coords for i in interior]
-        complete.append(Polygon(shell=shell, holes=holes))
-    return complete
+    # generate polygons with proper interiors
+    return [
+        Polygon(
+            shell=polygons[root.exterior],
+            holes=[polygons[i].exterior for i in tree[root].keys()],
+        )
+        for root in roots
+    ]
 
 
 def polygons_obb(polygons: Iterable[Polygon]):
@@ -864,17 +865,11 @@ def projected(
         return polygons[0]
     elif len(polygons) == 0:
         return None
-    # inflate each polygon before unioning to remove zero-size
-    # gaps then deflate the result after unioning by the same amount
-    # note the following provides a 25% speedup but needs
-    # more testing to see if it deflates to a decent looking
-    # result:
-    # polygon = ops.unary_union(
-    #    [p.buffer(padding,
-    #              join_style=2,
-    #              mitre_limit=1.5)
-    #     for p in polygons]).buffer(-padding)
-    return ops.unary_union([p.buffer(padding) for p in polygons]).buffer(-padding)
+
+    # in my tests this was substantially faster than `shapely.ops.unary_union`
+    return (
+        reduce_cascade(lambda a, b: a.union(b), polygons).buffer(padding).buffer(-padding)
+    )
 
 
 def second_moments(polygon: Polygon, return_centered=False):