Refactor volume() to use existing volume_polyhedron function

Simplified implementation by reusing the existing volume_polyhedron
function from compas.geometry instead of reimplementing the algorithm.
This reduces code duplication and improves maintainability.

Co-authored-by: Licini <17893605+Licini@users.noreply.github.com>

Author: Copilot

src/compas/datastructures/mesh/mesh.py

@@ -42,7 +42,6 @@
 from compas.geometry import distance_line_line
 from compas.geometry import distance_point_plane
 from compas.geometry import distance_point_point
-from compas.geometry import dot_vectors
 from compas.geometry import length_vector
 from compas.geometry import midpoint_line
 from compas.geometry import normal_polygon
@@ -53,6 +52,7 @@
 from compas.geometry import sum_vectors
 from compas.geometry import transform_points
 from compas.geometry import vector_average
+from compas.geometry import volume_polyhedron
 from compas.itertools import linspace
 from compas.itertools import pairwise
 from compas.itertools import window
@@ -3912,33 +3912,8 @@ def volume(self):
         if not self.is_closed():
             return None
 
-        volume = 0.0
-        for fkey in self.faces():
-            vertices = self.face_vertices(fkey)
-            # Get coordinates for all vertices of the face
-            coords = [self.vertex_coordinates(v) for v in vertices]
-
-            # Triangulate the face if it has more than 3 vertices
-            if len(coords) == 3:
-                triangles = [coords]
-            else:
-                # Use simple fan triangulation from first vertex
-                triangles = []
-                for i in range(1, len(coords) - 1):
-                    triangles.append([coords[0], coords[i], coords[i + 1]])
-
-            # Calculate signed volume contribution from each triangle
-            for triangle in triangles:
-                # Signed volume of tetrahedron formed by triangle and origin
-                # V = (1/6) * |a · (b × c)| where a, b, c are the vertices
-                a, b, c = triangle
-                # Calculate cross product of b and c
-                bc = cross_vectors(b, c)
-                # Calculate dot product with a
-                vol = dot_vectors(a, bc) / 6.0
-                volume += vol
-
-        return abs(volume)
+        vertices, faces = self.to_vertices_and_faces()
+        return abs(volume_polyhedron((vertices, faces)))
 
     def centroid(self):
         """Calculate the mesh centroid.