diff --git a/Geometry/clash.py b/Geometry/clash.py
index b6ae67f..9a96ab6 100644
--- a/Geometry/clash.py
+++ b/Geometry/clash.py
@@ -1,7 +1,12 @@
 from concurrent.futures import ProcessPoolExecutor, as_completed
 from typing import List, Tuple, Any, Optional
 
-import pymesh
+try:
+    import pymesh
+except ImportError:
+    from Geometry.mocks import mypymesh
+
+    pymesh = mypymesh
 
 from speckle_automate import AutomationContext
 
@@ -10,7 +15,7 @@ from Geometry.mesh import cast
 
 
 def detect_clashes_old(
-    reference_elements: List[Element], latest_elements: List[Element], _tolerance: float
+        reference_elements: List[Element], latest_elements: List[Element], _tolerance: float
 ) -> list[tuple[str, str, float]]:
     """
     Detect clashes between two sets of mesh elements using Pymesh.
@@ -41,11 +46,11 @@ def detect_clashes_old(
                         continue
 
                     intersection = pymesh.boolean(
-                        ref_pymesh, latest_pymesh, operation="intersection"
+                        latest_pymesh, operation="intersection"
                     )
 
                     if (
-                        intersection and intersection.volume > 0
+                            intersection and intersection.volume > 0
                     ):  # TODO: could tolerance relate to this?
                         severity = intersection.volume / min(
                             ref_pymesh.volume, latest_pymesh.volume
@@ -57,7 +62,7 @@ def detect_clashes_old(
 
 
 def check_for_clash(
-    ref_element: Element, latest_element: Element
+        ref_element: Element, latest_element: Element
 ) -> Optional[tuple[Any, Any, Any]]:
     """
     Check for a clash between two elements and calculate the severity of the clash.
@@ -78,7 +83,7 @@ def check_for_clash(
                 continue
 
             intersection = pymesh.boolean(
-                ref_pymesh, latest_pymesh, operation="intersection"
+                latest_pymesh, operation="intersection"
             )
             if intersection and intersection.volume > 0:
                 severity = intersection.volume / min(
@@ -89,7 +94,7 @@ def check_for_clash(
 
 
 def detect_clashes(
-    reference_elements: List[Element], latest_elements: List[Element], _tolerance: float
+        reference_elements: List[Element], latest_elements: List[Element], _tolerance: float
 ) -> List[Tuple[str, str, float]]:
     """
     Detect clashes between two sets of mesh elements using parallel processing.
@@ -118,10 +123,10 @@ def detect_clashes(
 
 
 def detect_and_report_clashes(
-    reference_elements: list[Element],
-    latest_elements: list[Element],
-    tolerance: float,
-    automate_context: AutomationContext,
+        reference_elements: list[Element],
+        latest_elements: list[Element],
+        tolerance: float,
+        automate_context: AutomationContext,
 ) -> list[tuple[str, str, float]]:
     clashes = detect_clashes(reference_elements, latest_elements, tolerance)
 
diff --git a/Geometry/mesh.py b/Geometry/mesh.py
index 75fe0fe..1b59123 100644
--- a/Geometry/mesh.py
+++ b/Geometry/mesh.py
@@ -1,11 +1,16 @@
-from typing import Union, Type, TYPE_CHECKING
+from typing import Union, Type
 
+try:
+    import pymesh
+except ImportError:
+    from Geometry.mocks import mypymesh
 
-import pymesh
-
+    pymesh = mypymesh
 
 import trimesh
 
+from Geometry.helpers import triangulate_face
+
 
 class MockPyMesh:
     def __init__(self, vertices, faces):
@@ -39,7 +44,7 @@ def pymesh_to_trimesh(mesh: pymesh.Mesh) -> trimesh.Trimesh:
 
 
 def cast(
-    mesh: Union[trimesh.Trimesh, pymesh.Mesh], target_type: Type
+        mesh: Union[trimesh.Trimesh, pymesh.Mesh], target_type: Type
 ) -> Union[trimesh.Trimesh, pymesh.Mesh]:
     """
     Casts a mesh object to a specified type.
@@ -74,7 +79,7 @@ def speckle_mesh_to_trimesh(input_mesh: SpeckleMesh) -> trimesh.Trimesh:
         face_vertex_count = input_mesh.faces[i]
         i += 1  # Skip the vertex count
 
-        face_vertex_indices = input_mesh.faces[i : i + face_vertex_count]
+        face_vertex_indices = input_mesh.faces[i: i + face_vertex_count]
 
         face_vertices = [
             Vector.from_list(vertices[idx].tolist()) for idx in face_vertex_indices
diff --git a/Geometry/mocks.py b/Geometry/mocks.py
new file mode 100644
index 0000000..935d809
--- /dev/null
+++ b/Geometry/mocks.py
@@ -0,0 +1,12 @@
+class mypymesh:
+    def __init__(self, vertices, faces):
+        self.vertices = vertices
+        self.faces = faces
+
+    @staticmethod
+    def boolean(_other, _operation):
+        return mypymesh([], [])
+
+    @property
+    def volume(self):
+        return 0
diff --git a/poetry.lock b/poetry.lock
index 3b1cafd..fe871b5 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -774,19 +774,6 @@ files = [
 [package.dependencies]
 typing-extensions = ">=4.6.0,<4.7.0 || >4.7.0"
 
-[[package]]
-name = "pymesh"
-version = "1.0.2"
-description = "Library for manipulating (Translate, Rotate and Scale) 3D data using numpy."
-optional = false
-python-versions = "*"
-files = [
-    {file = "pymesh-1.0.2.tar.gz", hash = "sha256:7032cd5c53cd9d93b31b6033bfdf7a61ca482ce4dc10d70411a1f392df095deb"},
-]
-
-[package.dependencies]
-numpy = "*"
-
 [[package]]
 name = "pytest"
 version = "7.4.3"
@@ -1287,4 +1274,4 @@ multidict = ">=4.0"
 [metadata]
 lock-version = "2.0"
 python-versions = "^3.10"
-content-hash = "5e736eb0d2aeb78aaf6b2252f4f3e011b6bca230716f2d0e07c29d3b3dc796ce"
+content-hash = "3abedc1c21df21ba5ab28f1ea6dc49c8a84c768e0f8f155e5c619ca3fd023765"
diff --git a/pyproject.toml b/pyproject.toml
index 7cae34d..ff104e3 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -9,7 +9,6 @@ readme = "README.md"
 python = "^3.10"
 specklepy = "2.17.11"
 trimesh = "^4.0.4"
-pymesh = "^1.0.2"
 
 [tool.poetry.group.dev.dependencies]
 black = "^23.3.0"
@@ -23,11 +22,11 @@ build-backend = "poetry.core.masonry.api"
 
 [tool.ruff]
 select = [
-  "E",   # pycodestyle
-  "F",   # pyflakes
-  "UP",  # pyupgrade
-  "D",   # pydocstyle
-  "I",   # isort
+    "E", # pycodestyle
+    "F", # pyflakes
+    "UP", # pyupgrade
+    "D", # pydocstyle
+    "I", # isort
 ]
 
 [tool.ruff.pydocstyle]