Add test for nurbs fitting surface pdm and triangulation.

test/surface/CMakeLists.txt

@@ -39,6 +39,13 @@ PCL_ADD_TEST(surface_poisson test_poisson
              LINK_WITH pcl_gtest pcl_io pcl_kdtree pcl_surface pcl_features
              ARGUMENTS "${PCL_SOURCE_DIR}/test/bun0.pcd")
 
+if(BUILD_surface_on_nurbs)
+  PCL_ADD_TEST(surface_on_nurbs test_on_nurbs
+               FILES test_on_nurbs.cpp
+               LINK_WITH pcl_gtest pcl_io pcl_kdtree pcl_surface pcl_features pcl_search
+               ARGUMENTS "${PCL_SOURCE_DIR}/test/bun0.pcd")
+endif()
+
 if(QHULL_FOUND)
   PCL_ADD_TEST(surface_convex_hull test_convex_hull
                FILES test_convex_hull.cpp

test/surface/test_on_nurbs.cpp

@@ -0,0 +1,123 @@
+/*
+* SPDX-License-Identifier: BSD-3-Clause
+*
+*  Point Cloud Library (PCL) - www.pointclouds.org
+*  Copyright (c) 2025-, Open Perception Inc.
+*
+*  All rights reserved
+*/
+
+#include <pcl/test/gtest.h>
+
+#include <pcl/common/common.h>
+#include <pcl/io/pcd_io.h>
+#include <pcl/point_cloud.h>
+#include <pcl/point_types.h>
+#include <pcl/surface/on_nurbs/nurbs_data.h>
+#include <pcl/surface/on_nurbs/fitting_surface_pdm.h>
+#include <pcl/surface/on_nurbs/triangulation.h>
+
+#include <cmath>
+
+using namespace pcl;
+using namespace pcl::io;
+
+using Point = pcl::PointXYZ;
+
+PointCloud<Point>::Ptr cloud (new PointCloud<Point>);
+
+void
+PointCloud2Vector3d (pcl::PointCloud<Point>::Ptr cloud, pcl::on_nurbs::vector_vec3d &data)
+{
+  for (const auto &p : *cloud)
+  {
+    if (!std::isnan (p.x) && !std::isnan (p.y) && !std::isnan (p.z))
+      data.emplace_back (p.x, p.y, p.z);
+  }
+}
+
+//////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+TEST (PCL, on_nurbs_fitting_surface_pdm)
+{
+  // ############################################################################
+  // fit B-spline surface
+  pcl::on_nurbs::NurbsDataSurface data;
+  PointCloud2Vector3d (cloud, data.interior);
+  // parameters
+  unsigned order (3);
+  unsigned refinement (5);
+  unsigned iterations (10);
+  unsigned mesh_resolution (256);
+
+  pcl::on_nurbs::FittingSurface::Parameter params;
+  params.interior_smoothness = 0.2;
+  params.interior_weight = 1.0;
+  params.boundary_smoothness = 0.2;
+  params.boundary_weight = 0.0;
+
+  // initialize
+  ON_NurbsSurface nurbs = pcl::on_nurbs::FittingSurface::initNurbsPCABoundingBox (order, &data);
+  pcl::on_nurbs::FittingSurface fit (&data, nurbs);
+  //  fit.setQuiet (false); // enable/disable debug output
+
+  // mesh for visualization
+  pcl::PolygonMesh mesh;
+  pcl::PointCloud<pcl::PointXYZ>::Ptr mesh_cloud (new pcl::PointCloud<pcl::PointXYZ>);
+  std::vector<pcl::Vertices> mesh_vertices;
+  std::string mesh_id = "mesh_nurbs";
+  pcl::on_nurbs::Triangulation::convertSurface2PolygonMesh (fit.m_nurbs, mesh, mesh_resolution);
+
+  // surface refinement
+  for (unsigned i = 0; i < refinement; i++)
+  {
+    fit.refine (0);
+    fit.refine (1);
+    fit.assemble (params);
+    fit.solve ();
+    pcl::on_nurbs::Triangulation::convertSurface2Vertices (fit.m_nurbs, mesh_cloud, mesh_vertices, mesh_resolution);
+  }
+
+  // surface fitting with final refinement level
+  for (unsigned i = 0; i < iterations; i++)
+  {
+    fit.assemble (params);
+    fit.solve ();
+    pcl::on_nurbs::Triangulation::convertSurface2Vertices (fit.m_nurbs, mesh_cloud, mesh_vertices, mesh_resolution);
+  }
+
+  ASSERT_EQ (mesh.polygons.size (), 131072);
+  // All polygons should be triangles
+  for (const auto & polygon : mesh.polygons)
+    EXPECT_EQ (polygon.vertices.size (), 3);
+
+  EXPECT_EQ (mesh.polygons[10].vertices[0], 5);
+  EXPECT_EQ (mesh.polygons[10].vertices[1], 6);
+  EXPECT_EQ (mesh.polygons[10].vertices[2], 263);
+
+  EXPECT_EQ (mesh.polygons[200].vertices[0], 100);
+  EXPECT_EQ (mesh.polygons[200].vertices[1], 101);
+  EXPECT_EQ (mesh.polygons[200].vertices[2], 358);
+
+  EXPECT_EQ (mesh.polygons[1000].vertices[0], 501);
+  EXPECT_EQ (mesh.polygons[1000].vertices[1], 502);
+  EXPECT_EQ (mesh.polygons[1000].vertices[2], 759);
+}
+
+/* ---[ */
+int
+main (int argc, char** argv)
+{
+  if (argc < 2)
+  {
+    std::cerr << "No test file given. Please download `bun0.pcd` and pass its path to the test." << std::endl;
+    return (-1);
+  }
+
+  // Load file
+  loadPCDFile (argv[1], *cloud);
+
+  // Testing
+  testing::InitGoogleTest (&argc, argv);
+  return (RUN_ALL_TESTS ());
+}
+/* ]--- */