ADD measure.

Author: petrasvestartas

CMakeLists.txt

@@ -228,3 +228,4 @@ endfunction()
 add_nanobind_module(booleans_ext src/booleans.cpp)
 add_nanobind_module(meshing_ext src/meshing.cpp)
 add_nanobind_module(intersections_ext src/intersections.cpp)
+add_nanobind_module(measure_ext src/measure.cpp)

docs/examples/example_measure.py

@@ -0,0 +1,38 @@
+from compas.datastructures import Mesh
+from compas.geometry import Box
+from line_profiler import profile
+
+from compas_cgal.measure import mesh_area
+from compas_cgal.measure import mesh_centroid
+from compas_cgal.measure import mesh_volume
+
+
+@profile
+def main(mesh):
+    """Mesh measurement methods."""
+    area = mesh_area(mesh)
+    volume = mesh_volume(mesh)
+    centroid = mesh_centroid(mesh)
+    return area, volume, centroid
+
+
+# ==============================================================================
+# Input geometry
+# ==============================================================================
+
+box = Box(1)
+v, f = box.to_vertices_and_faces()
+mesh = Mesh.from_vertices_and_faces(v, f)
+mesh.quads_to_triangles()
+V, F = mesh.to_vertices_and_faces()
+
+
+# ==============================================================================
+# Compute
+# ==============================================================================
+
+result = main((V, F))
+
+print("Area:", result[0])
+print("Volume:", result[1])
+print("Centroid:", result[2])

src/compas_cgal/measure.py

@@ -0,0 +1,81 @@
+import numpy as np
+from compas.geometry import Point
+from compas.plugins import plugin
+
+from compas_cgal import measure_ext
+
+from .types import VerticesFaces
+
+
+def mesh_area(mesh: VerticesFaces) -> float:
+    """Compute the area of a triangle mesh.
+
+    Parameters
+    ----------
+    mesh : :attr:`compas_cgal.types.VerticesFaces`
+        The mesh.
+
+    Returns
+    -------
+    float
+        The area of the mesh.
+
+    """
+    V, F = mesh
+    V = np.asarray(V, dtype=np.float64, order="C")
+    F = np.asarray(F, dtype=np.int32, order="C")
+    return measure_ext.area(V, F)
+
+
+@plugin(category="trimesh", pluggable_name="trimesh_volume")
+def mesh_volume(mesh: VerticesFaces) -> float:
+    """Compute the volume of a closed triangle mesh.
+
+    Parameters
+    ----------
+    mesh : :attr:`compas_cgal.types.VerticesFaces`
+        The mesh.
+
+    Returns
+    -------
+    float
+        The volume of the mesh.
+
+    Examples
+    --------
+    >>> from compas.geometry import Box
+    >>> from compas_cgal.measure import mesh_volume
+
+    >>> box = Box(1)
+    >>> mesh = box.to_vertices_and_faces(triangulated=True)
+
+    >>> mesh_volume(mesh)
+    1.0
+
+    """
+    V, F = mesh
+    V = np.asarray(V, dtype=np.float64, order="C")
+    F = np.asarray(F, dtype=np.int32, order="C")
+    return measure_ext.volume(V, F)
+
+
+def mesh_centroid(mesh: VerticesFaces) -> list[float]:
+    """Compute the centroid of a the volume of a closed triangle mesh.
+
+    Parameters
+    ----------
+    mesh : :attr:`compas_cgal.types.VerticesFaces`
+        The mesh.
+
+    Returns
+    -------
+    list
+        The centroid of the mesh.
+
+    """
+    V, F = mesh
+    V = np.asarray(V, dtype=np.float64, order="C")
+    F = np.asarray(F, dtype=np.int32, order="C")
+    vector_of_double: measure_ext.VectorDouble = measure_ext.centroid(V, F)
+    point = Point(*vector_of_double)
+    return point

src/measure.cpp

@@ -0,0 +1,59 @@
+#include "measure.h"
+
+double
+pmp_area(
+    Eigen::Ref<const compas::RowMatrixXd> vertices,
+    Eigen::Ref<const compas::RowMatrixXi> faces)
+{
+    compas::Mesh mesh = compas::mesh_from_vertices_and_faces(vertices, faces);
+    double area = CGAL::Polygon_mesh_processing::area(mesh);
+    return area;
+}
+
+double
+pmp_volume(
+    Eigen::Ref<const compas::RowMatrixXd> vertices,
+    Eigen::Ref<const compas::RowMatrixXi> faces)
+{
+    compas::Mesh mesh = compas::mesh_from_vertices_and_faces(vertices, faces);
+    double volume = CGAL::Polygon_mesh_processing::volume(mesh);
+    int a = 0;
+    return volume;
+}
+
+std::vector<double>
+pmp_centroid(
+    Eigen::Ref<const compas::RowMatrixXd> vertices,
+    Eigen::Ref<const compas::RowMatrixXi> faces)
+{
+    compas::Mesh mesh = compas::mesh_from_vertices_and_faces(vertices, faces);
+    compas::Kernel::Point_3 centroid = CGAL::Polygon_mesh_processing::centroid(mesh);
+    return std::vector<double>{centroid.x(), centroid.y(), centroid.z()};
+}
+
+
+NB_MODULE(measure_ext, m) {
+
+    nb::bind_vector<std::vector<double>>(m, "VectorDouble"); // Be aware that both Pybind11 and Nanobind makes copy for vectors
+
+    m.def(
+        "area",
+        &pmp_area,
+        "Calculate the surface area of a mesh",
+        "vertices"_a,
+        "faces"_a);
+
+    m.def(
+        "volume",
+        &pmp_volume,
+        "Calculate the volume enclosed by a mesh",
+        "vertices"_a,
+        "faces"_a);
+
+    m.def(
+        "centroid",
+        &pmp_centroid,
+        "Calculate the centroid of a mesh",
+        "vertices"_a,
+        "faces"_a);
+}

src/measure.h

@@ -0,0 +1,43 @@
+#pragma once
+
+#include "compas.h"
+
+// CGAL measure
+#include <CGAL/Polygon_mesh_processing/measure.h>
+#include <CGAL/Point_3.h>
+
+/**
+ * @brief Computes the surface area of a triangle mesh.
+ * 
+ * @param vertices Matrix of vertex positions as Nx3 matrix in row-major order (float64)
+ * @param faces Matrix of face indices as Mx3 matrix in row-major order (int32)
+ * @return double The total surface area of the mesh
+ */
+double
+pmp_area(
+    Eigen::Ref<const compas::RowMatrixXd> vertices,
+    Eigen::Ref<const compas::RowMatrixXi> faces);
+
+/**
+ * @brief Computes the volume of a closed triangle mesh.
+ * 
+ * @param vertices Matrix of vertex positions as Nx3 matrix in row-major order (float64)
+ * @param faces Matrix of face indices as Mx3 matrix in row-major order (int32)
+ * @return double The volume enclosed by the mesh. Returns 0 if the mesh is not closed.
+ */
+double
+pmp_volume(
+    Eigen::Ref<const compas::RowMatrixXd> vertices,
+    Eigen::Ref<const compas::RowMatrixXi> faces);
+
+/**
+ * @brief Computes the centroid (center of mass) of a triangle mesh.
+ * 
+ * @param vertices Matrix of vertex positions as Nx3 matrix in row-major order (float64)
+ * @param faces Matrix of face indices as Mx3 matrix in row-major order (int32)
+ * @return std::vector<double> A vector containing the x,y,z coordinates of the mesh centroid
+ */
+std::vector<double>
+pmp_centroid(
+    Eigen::Ref<const compas::RowMatrixXd> vertices,
+    Eigen::Ref<const compas::RowMatrixXi> faces);

tests/test_measure.py

@@ -0,0 +1,40 @@
+"""Tests for COMPAS CGAL measure functionality."""
+
+import pytest
+from compas.geometry import Box
+from compas.datastructures import Mesh
+from compas_cgal.measure import mesh_area, mesh_volume, mesh_centroid
+
+
+def test_area():
+    """Test area computation with a unit cube."""
+    box = Box.from_width_height_depth(1, 1, 1)
+    mesh = Mesh.from_vertices_and_faces(*box.to_vertices_and_faces())
+    mesh.quads_to_triangles()
+    V, F = mesh.to_vertices_and_faces()
+
+    # Unit cube has 6 faces, each 1x1 = total area of 6
+    assert pytest.approx(mesh_area((V, F))) == 6.0
+
+
+def test_volume():
+    """Test volume computation with a unit cube."""
+    box = Box.from_width_height_depth(1, 1, 1)
+    mesh = Mesh.from_vertices_and_faces(*box.to_vertices_and_faces())
+    mesh.quads_to_triangles()
+    V, F = mesh.to_vertices_and_faces()
+
+    # Unit cube has volume of 1
+    assert pytest.approx(mesh_volume((V, F))) == 1.0
+
+
+def test_centroid():
+    """Test centroid computation with a unit cube."""
+    box = Box.from_width_height_depth(1, 1, 1)
+    mesh = Mesh.from_vertices_and_faces(*box.to_vertices_and_faces())
+    mesh.quads_to_triangles()
+    V, F = mesh.to_vertices_and_faces()
+
+    # Centroid should be at origin (0,0,0)
+    result = mesh_centroid((V, F))
+    assert pytest.approx(result) == [0.0, 0.0, 0.0]