fix: exception when calling geometry of compas.datastructures.Part without features assigned

Author: gonzalocasas

CHANGELOG.md

@@ -53,6 +53,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 * Fixed `compas_ghpython.artists.VolMeshArtist.draw` and `compas_ghpython.artists.VolMeshArtist.draw_cells`.
 * Fixed `compas_rhino.artists.VolMeshArtist.draw` and `compas_rhino.artists.VolMeshArtist.draw_cells`.
 * Improved error messages when artist instance cannot be created.
+* Fixed exception when calculating geometry of `compas.datastructures.Part` without features.
 
 ### Removed
 

src/compas/datastructures/assembly/part.py

@@ -144,13 +144,17 @@ def frame(self, frame):
     def geometry(self):
         # TODO: this is a temp solution
         # TODO: add memoization or some other kind of caching
-        A = Mesh.from_shape(self.shape)
-        for shape, operation in self.features:
-            A.quads_to_triangles()
-            B = Mesh.from_shape(shape)
-            B.quads_to_triangles()
-            A = Part.operations[operation](A.to_vertices_and_faces(), B.to_vertices_and_faces())
-        geometry = Shape(*A)
+        if self.features:
+            A = Mesh.from_shape(self.shape)
+            for shape, operation in self.features:
+                A.quads_to_triangles()
+                B = Mesh.from_shape(shape)
+                B.quads_to_triangles()
+                A = Part.operations[operation](A.to_vertices_and_faces(), B.to_vertices_and_faces())
+            geometry = Shape(*A)
+        else:
+            geometry = Shape(*self.shape.to_vertices_and_faces())
+
         T = Transformation.from_frame_to_frame(Frame.worldXY(), self.frame)
         geometry.transform(T)
         return geometry