Adds volume and surface area properties

Adds `volume` and `surface_area` properties to the `TessellatedBrep`
class. These properties calculate the volume and surface area of
closed meshes using COMPAS geometry functions. This allows to
easily extract geometrical properties from tessellated representations.

Author: Licini

CHANGELOG.md

@@ -9,6 +9,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+* Added `volume` property to `TessellatedBrep` class for calculating volume of closed meshes using COMPAS geometry functions
+* Added `surface_area` property to `TessellatedBrep` class for calculating surface area by summing face areas
+
 ### Changed
 
 ### Removed

scripts/7.1_geometry_ops.py

@@ -0,0 +1,10 @@
+from compas_ifc.model import Model
+
+model = Model("data/wall-with-opening-and-window.ifc")
+model.print_summary()
+
+unit = model.unit
+
+element = model.get_entities_by_type("IfcWindow")[0]
+print("Volume:", element.geometry.volume, unit + "³")
+print("Surface Area:", element.geometry.surface_area, unit + "²")

src/compas_ifc/brep/tessellatedbrep.py

@@ -1,8 +1,10 @@
 import numpy as np
 from compas.datastructures import Mesh
 from compas.geometry import Geometry
+from compas.geometry import area_polygon
 from compas.geometry import bounding_box
 from compas.geometry import transform_points_numpy
+from compas.geometry import volume_polyhedron
 
 
 class TessellatedBrep(Geometry):
@@ -41,3 +43,65 @@ def obb(self):
         from compas.geometry import oriented_bounding_box_numpy
 
         return Box.from_bounding_box(oriented_bounding_box_numpy(self.vertices))
+
+    @property
+    def volume(self):
+        """Calculate the volume of the tessellated BREP by converting to mesh.
+
+        Returns
+        -------
+        float or None
+            The volume of the BREP if the mesh is closed, None otherwise.
+        """
+        # Handle edge case: empty vertices or faces
+        if len(self.vertices) == 0 or len(self.faces) == 0:
+            return None
+
+        try:
+            mesh = self.to_mesh()
+
+            # Check if mesh is closed - volume can only be calculated for closed meshes
+            if not mesh.is_closed():
+                return None
+
+            # Get vertices and faces for volume calculation
+            vertices, faces = mesh.to_vertices_and_faces()
+
+            # Calculate volume using COMPAS geometry function
+            return volume_polyhedron((vertices, faces))
+
+        except Exception:
+            # Return None if any error occurs during calculation
+            return None
+
+    @property
+    def surface_area(self):
+        """Calculate the surface area of the tessellated BREP by converting to mesh.
+
+        Returns
+        -------
+        float or None
+            The surface area of the BREP, or None if calculation fails.
+        """
+        # Handle edge case: empty vertices or faces
+        if len(self.vertices) == 0 or len(self.faces) == 0:
+            return None
+
+        try:
+            mesh = self.to_mesh()
+
+            # Calculate total surface area by summing face areas
+            total_area = 0.0
+            for face_key in mesh.faces():
+                # Get face vertices coordinates
+                face_vertices = [mesh.vertex_coordinates(vertex) for vertex in mesh.face_vertices(face_key)]
+
+                # Calculate area of this face using COMPAS geometry function
+                face_area = area_polygon(face_vertices)
+                total_area += face_area
+
+            return total_area
+
+        except Exception:
+            # Return None if any error occurs during calculation
+            return None