Centralize trimesh import

configure_trimesh_scad.py

@@ -1,6 +1,6 @@
 import os
 import sys
-import trimesh
+from parametric_cad.core import tm
 import logging
 
 logging.basicConfig(filename='install_debug.log', level=logging.DEBUG, format='%(asctime)s - %(levelname)s - %(message)s')
@@ -15,15 +15,15 @@ def configure_trimesh_scad():
     print("Configuring trimesh to use OpenSCAD engine...")
     logging.info("Checking trimesh module availability")
 
-    # Check if trimesh is available
-    try:
-        import trimesh
-        logging.info("trimesh module found")
-        print("trimesh module found.")
-    except ImportError:
-        logging.error("trimesh module not found")
-        print("trimesh module not found! Please ensure it is installed via 'pip install trimesh'.")
-        sys.exit(1)
+    # Check if trimesh (the mesh backend) is available
+    try:
+        _ = tm.__version__
+        logging.info("trimesh module found")
+        print("trimesh module found.")
+    except Exception:
+        logging.error("trimesh module not found")
+        print("trimesh module not found! Please ensure it is installed via 'pip install trimesh'.")
+        sys.exit(1)
 
     # Check if OpenSCAD executable exists
     logging.debug(f"Verifying OpenSCAD existence at {openscad_path}")

parametric_cad/__init__.py

@@ -1,8 +1,9 @@
 """Consolidated parametric_cad package."""
 
+from .core import tm
 from .primitives.box import Box
 from .primitives.gear import SpurGear
 from .mechanisms.butthinge import ButtHinge
 from .export.stl import STLExporter
 
-__all__ = ["Box", "SpurGear", "ButtHinge", "STLExporter"]
+__all__ = ["tm", "Box", "SpurGear", "ButtHinge", "STLExporter"]

parametric_cad/core.py

@@ -0,0 +1,15 @@
+"""Backend access for parametric_cad.
+
+This module centralizes interaction with the mesh backend so other
+parts of the package do not need to import the backend directly.
+Currently :mod:`trimesh` provides all geometry functionality, but this
+wrapper allows the backend to be swapped or mocked easily.
+"""
+
+import trimesh as _trimesh
+
+# Public alias so that other modules can use the backend without
+# importing ``trimesh`` themselves.
+tm = _trimesh
+
+__all__ = ["tm"]

parametric_cad/examples/hollow_box.py

@@ -1,6 +1,5 @@
 from parametric_cad.primitives.box import Box
 from parametric_cad.export.stl import STLExporter
-import trimesh
 
 outer = Box(100, 60, 40).at(0, 0, 0)
 inner = Box(90, 50, 30).at(5, 5, 5)

parametric_cad/export/stl.py

@@ -1,5 +1,4 @@
-import trimesh
-import trimesh.exchange.stl
+from parametric_cad.core import tm
 import os
 import logging
 import numpy as np
@@ -18,7 +17,7 @@ class STLExporter:
         os.makedirs(self.output_dir, exist_ok=True)
 
     def _ensure_mesh(self, obj):
-        if isinstance(obj, trimesh.Trimesh):
+        if isinstance(obj, tm.Trimesh):
             return obj
         if hasattr(obj, "mesh"):
             m = obj.mesh
@@ -31,7 +30,7 @@ class STLExporter:
 
     def export_meshes(self, objs, base_filename, timestamp=False, preview=True):
         meshes = [self._ensure_mesh(o) for o in objs]
-        combined = trimesh.util.concatenate(meshes)
+        combined = tm.util.concatenate(meshes)
         if not combined.is_watertight or combined.vertices.shape[0] == 0:
             repaired = combined.fill_holes()
             if repaired is not False:
@@ -47,7 +46,7 @@ class STLExporter:
         if self.binary:
             combined.export(path, file_type="stl")
         else:
-            text = trimesh.exchange.stl.export_stl_ascii(combined)
+            text = tm.exchange.stl.export_stl_ascii(combined)
             with open(path, "w", encoding="utf-8") as f:
                 f.write(text)
         logging.info(f"Exported STL to {path}")

parametric_cad/mechanisms/butthinge.py

@@ -1,6 +1,6 @@
-import trimesh
-import numpy as np
-from parametric_cad.export.stl import STLExporter
+from parametric_cad.core import tm
+import numpy as np
+from parametric_cad.export.stl import STLExporter
 
 class ButtHinge:
     def __init__(self, leaf_length=50.0, leaf_width=25.0, leaf_thickness=2.0, knuckles=5, pin_diameter=3.0):
@@ -23,7 +23,7 @@ class ButtHinge:
         self.exporter = STLExporter()
 
     def _create_hinge(self):
-        """Create a trimesh object representing the butt hinge."""
+        """Create a trimesh object representing the butt hinge."""
         # Create two leaves
         leaf_vertices = np.array([
             [0, 0, 0], [self.leaf_length, 0, 0], [self.leaf_length, self.leaf_width, 0],
@@ -35,7 +35,7 @@ class ButtHinge:
             [0, 1, 5], [0, 5, 4], [2, 3, 7], [2, 7, 6],
             [0, 3, 7], [0, 7, 4], [1, 2, 6], [1, 6, 5]
         ])
-        leaf1 = trimesh.Trimesh(vertices=leaf_vertices, faces=leaf_faces, process=False)
+        leaf1 = tm.Trimesh(vertices=leaf_vertices, faces=leaf_faces, process=False)
 
         # Second leaf, offset for hinge alignment
         leaf2 = leaf1.copy()
@@ -46,7 +46,7 @@ class ButtHinge:
         knuckle_spacing = self.leaf_length / (self.knuckles + 1)
         for i in range(self.knuckles):
             z_pos = knuckle_spacing * (i + 1)
-            knuckle = trimesh.creation.cylinder(
+            knuckle = tm.creation.cylinder(
                 radius=self.pin_diameter / 2,
                 height=self.leaf_thickness + 0.1,  # Slight overlap for union
                 sections=16
@@ -55,7 +55,7 @@ class ButtHinge:
             knuckle_meshes.append(knuckle)
 
         # Combine leaves and knuckles
-        hinge = trimesh.util.concatenate([leaf1, leaf2] + knuckle_meshes)
+        hinge = tm.util.concatenate([leaf1, leaf2] + knuckle_meshes)
         return hinge
 
     def mesh(self):

parametric_cad/primitives/box.py

@@ -1,4 +1,4 @@
-import trimesh
+from parametric_cad.core import tm
 
 class Box:
     def __init__(self, width, depth, height):
@@ -12,6 +12,6 @@ class Box:
         return self
 
     def mesh(self):
-        box = trimesh.creation.box(extents=(self.width, self.depth, self.height))
+        box = tm.creation.box(extents=(self.width, self.depth, self.height))
         box.apply_translation(self._position)
         return box

parametric_cad/primitives/cylinder.py

@@ -1,4 +1,4 @@
-import trimesh
+from parametric_cad.core import tm
 
 class Cylinder:
     def __init__(self, radius, height, sections=32):
@@ -12,7 +12,7 @@ class Cylinder:
         return self
 
     def mesh(self):
-        cyl = trimesh.creation.cylinder(radius=self.radius, height=self.height,
-                                        sections=self.sections)
+        cyl = tm.creation.cylinder(radius=self.radius, height=self.height,
+                                   sections=self.sections)
         cyl.apply_translation(self._position)
         return cyl

parametric_cad/primitives/gear.py

@@ -1,5 +1,5 @@
 import numpy as np
-import trimesh
+from parametric_cad.core import tm
 from shapely.geometry import Polygon
 from math import pi, sin, cos, tan
 import logging
@@ -75,21 +75,21 @@ class SpurGear:
             polygon = polygon.buffer(0)
             logging.warning("Tooth polygon was invalid, repaired with buffer")
 
-        tooth_mesh = trimesh.creation.extrude_polygon(polygon, self.width, engine='triangle')
+        tooth_mesh = tm.creation.extrude_polygon(polygon, self.width, engine='triangle')
         logging.debug(f"Extruded tooth mesh with {len(tooth_mesh.vertices)} vertices")
 
         all_teeth = []
         for i in range(self.teeth):
             angle = 2 * pi * i / self.teeth
-            rot = trimesh.transformations.rotation_matrix(angle, [0, 0, 1])
+            rot = tm.transformations.rotation_matrix(angle, [0, 0, 1])
             rotated_tooth = tooth_mesh.copy().apply_transform(rot)
             all_teeth.append(rotated_tooth)
             logging.debug(f"Added tooth {i+1}/{self.teeth}")
 
-        gear_body = trimesh.util.concatenate(all_teeth)
+        gear_body = tm.util.concatenate(all_teeth)
         logging.debug(f"Combined {self.teeth} teeth into gear body with {len(gear_body.vertices)} vertices")
 
-        bore = trimesh.creation.cylinder(radius=self.bore_diameter / 2, height=self.width + 0.1)
+        bore = tm.creation.cylinder(radius=self.bore_diameter / 2, height=self.width + 0.1)
         bore.apply_translation([0, 0, self.width / 2])
         try:
             gear = gear_body.difference(bore, engine='scad')
@@ -107,7 +107,7 @@ class SpurGear:
                 angle = 2 * pi * i / self.hole_count
                 x = cos(angle) * self.hole_radius
                 y = sin(angle) * self.hole_radius
-                hole = trimesh.creation.cylinder(radius=self.hole_diameter / 2, height=self.width + 0.1)
+                hole = tm.creation.cylinder(radius=self.hole_diameter / 2, height=self.width + 0.1)
                 hole.apply_translation([x, y, self.width / 2])
                 if not hole.is_volume:
                     hole = hole.convex_hull

parametric_cad/primitives/sphere.py

@@ -1,4 +1,4 @@
-import trimesh
+from parametric_cad.core import tm
 
 class Sphere:
     def __init__(self, radius, subdivisions=3):
@@ -11,7 +11,7 @@ class Sphere:
         return self
 
     def mesh(self):
-        sph = trimesh.creation.icosphere(subdivisions=self.subdivisions,
-                                         radius=self.radius)
+        sph = tm.creation.icosphere(subdivisions=self.subdivisions,
+                                    radius=self.radius)
         sph.apply_translation(self._position)
         return sph

tests/test_export.py

@@ -1,5 +1,5 @@
 import os
-import trimesh
+from parametric_cad.core import tm
 from parametric_cad.primitives.box import Box
 from parametric_cad.primitives.cylinder import Cylinder
 from parametric_cad.primitives.sphere import Sphere
@@ -14,14 +14,14 @@ def test_stl_exporter(tmp_path):
     assert path == str(tmp_path / "test_box.stl")
     with open(path, "r", encoding="utf-8") as f:
         contents = f.read()
-    mesh = trimesh.util.concatenate([box.mesh()])
+    mesh = tm.util.concatenate([box.mesh()])
     if not mesh.is_watertight or mesh.vertices.shape[0] == 0:
         repaired = mesh.fill_holes()
         if repaired is not False:
             mesh = repaired
         else:
             mesh = mesh.convex_hull
-    expected = trimesh.exchange.stl.export_stl_ascii(mesh)
+    expected = tm.exchange.stl.export_stl_ascii(mesh)
     assert contents == expected
 
 
@@ -35,12 +35,12 @@ def test_ascii_stl_multiple_objects(tmp_path):
     assert path == str(tmp_path / "combo.stl")
     with open(path, "r", encoding="utf-8") as f:
         contents = f.read()
-    mesh = trimesh.util.concatenate([box.mesh(), cyl.mesh(), sph.mesh()])
+    mesh = tm.util.concatenate([box.mesh(), cyl.mesh(), sph.mesh()])
     if not mesh.is_watertight or mesh.vertices.shape[0] == 0:
         repaired = mesh.fill_holes()
         if repaired is not False:
             mesh = repaired
         else:
             mesh = mesh.convex_hull
-    expected = trimesh.exchange.stl.export_stl_ascii(mesh)
+    expected = tm.exchange.stl.export_stl_ascii(mesh)
     assert contents == expected

tests/test_mechanisms.py

@@ -1,6 +1,6 @@
 import numpy as np
 import pytest
-import trimesh
+from parametric_cad.core import tm
 
 from parametric_cad.mechanisms.butthinge import ButtHinge
 
@@ -8,7 +8,7 @@ from parametric_cad.mechanisms.butthinge import ButtHinge
 def test_butthinge_mesh_and_translation():
     hinge = ButtHinge()
     mesh = hinge.mesh()
-    assert isinstance(mesh, trimesh.Trimesh)
+    assert isinstance(mesh, tm.Trimesh)
     original_centroid = mesh.centroid.copy()
     hinge.at(1.0, 2.0, 3.0)
     translated_centroid = hinge.mesh().centroid

tests/test_primitives.py

@@ -1,6 +1,6 @@
 import pytest
 import numpy as np
-import trimesh
+from parametric_cad.core import tm
 from math import cos, pi
 
 from parametric_cad.primitives.box import Box
@@ -30,7 +30,7 @@ def test_cylinder_and_sphere_meshes():
     sph = Sphere(radius=1.0).at(-0.5, -0.5, 0)
     cyl_mesh = cyl.mesh()
     sph_mesh = sph.mesh()
-    assert isinstance(cyl_mesh, trimesh.Trimesh)
-    assert isinstance(sph_mesh, trimesh.Trimesh)
+    assert isinstance(cyl_mesh, tm.Trimesh)
+    assert isinstance(sph_mesh, tm.Trimesh)
     assert cyl_mesh.is_watertight
     assert sph_mesh.is_watertight