Triangle Mesh

triangle_mesh_connected_components.py

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import open3d as o3d
import numpy as np
import copy

if __name__ == "__main__":
    bunny = o3d.data.BunnyMesh()
    mesh = o3d.io.read_triangle_mesh(bunny.path)
    mesh.compute_vertex_normals()

    mesh = mesh.subdivide_midpoint(number_of_iterations=2)
    vert = np.asarray(mesh.vertices)
    min_vert, max_vert = vert.min(axis=0), vert.max(axis=0)
    for _ in range(30):
        cube = o3d.geometry.TriangleMesh.create_box()
        cube.scale(0.005, center=cube.get_center())
        cube.translate(
            (
                np.random.uniform(min_vert[0], max_vert[0]),
                np.random.uniform(min_vert[1], max_vert[1]),
                np.random.uniform(min_vert[2], max_vert[2]),
            ),
            relative=False,
        )
        mesh += cube
    mesh.compute_vertex_normals()
    print("Displaying input mesh ...")
    o3d.visualization.draw([mesh])

    print("Clustering connected triangles ...")
    with o3d.utility.VerbosityContextManager(
            o3d.utility.VerbosityLevel.Debug) as cm:
        triangle_clusters, cluster_n_triangles, cluster_area = (
            mesh.cluster_connected_triangles())
    triangle_clusters = np.asarray(triangle_clusters)
    cluster_n_triangles = np.asarray(cluster_n_triangles)
    cluster_area = np.asarray(cluster_area)

    print("Displaying mesh with small clusters removed ...")
    mesh_0 = copy.deepcopy(mesh)
    triangles_to_remove = cluster_n_triangles[triangle_clusters] < 100
    mesh_0.remove_triangles_by_mask(triangles_to_remove)
    o3d.visualization.draw([mesh_0])

triangle_mesh_cropping.py

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import open3d as o3d
import numpy as np
import copy

if __name__ == "__main__":
    knot_mesh = o3d.data.KnotMesh()
    mesh = o3d.io.read_triangle_mesh(knot_mesh.path)
    mesh.compute_vertex_normals()
    print("Displaying original mesh ...")
    o3d.visualization.draw([mesh])

    print("Displaying mesh of only the first half triangles ...")
    mesh_cropped = copy.deepcopy(mesh)
    mesh_cropped.triangles = o3d.utility.Vector3iVector(
        np.asarray(mesh_cropped.triangles)[:len(mesh_cropped.triangles) //
                                           2, :])
    mesh_cropped.triangle_normals = o3d.utility.Vector3dVector(
        np.asarray(mesh_cropped.triangle_normals)
        [:len(mesh_cropped.triangle_normals) // 2, :])
    print(mesh_cropped.triangles)
    o3d.visualization.draw([mesh_cropped])

triangle_mesh_deformation.py

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import numpy as np
import open3d as o3d
import time
import os
import sys

pyexample_path = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
sys.path.append(pyexample_path)

import open3d_example as o3dex


def problem0():
    mesh = o3dex.get_plane_mesh(height=1, width=1)
    mesh = mesh.subdivide_midpoint(3)
    vertices = np.asarray(mesh.vertices)
    static_ids = [
        1, 46, 47, 48, 16, 51, 49, 50, 6, 31, 33, 32, 11, 26, 27, 25, 0, 64, 65,
        20, 66, 68, 67, 7, 69, 71, 70, 22, 72, 74, 73, 3, 15, 44, 43, 45, 5, 41,
        40, 42, 13, 39, 37, 38, 2, 56, 55, 19, 61, 60, 59, 8, 76, 75, 77, 23
    ]
    static_positions = []
    for id in static_ids:
        static_positions.append(vertices[id])
    handle_ids = [4]
    handle_positions = [vertices[4] + np.array((0, 0, 0.4))]

    return mesh, static_ids + handle_ids, static_positions + handle_positions


def problem1():
    mesh = o3dex.get_plane_mesh(height=1, width=1)
    mesh = mesh.subdivide_midpoint(3)
    vertices = np.asarray(mesh.vertices)
    static_ids = [
        1, 46, 15, 43, 5, 40, 13, 38, 2, 56, 37, 39, 42, 41, 45, 44, 48, 47
    ]
    static_positions = []
    for id in static_ids:
        static_positions.append(vertices[id])
    handle_ids = [21]
    handle_positions = [vertices[21] + np.array((0, 0, 0.4))]

    return mesh, static_ids + handle_ids, static_positions + handle_positions


def problem2():
    armadillo_data = o3d.data.ArmadilloMesh()
    mesh = o3d.io.read_triangle_mesh(armadillo_data.path)
    vertices = np.asarray(mesh.vertices)
    static_ids = [idx for idx in np.where(vertices[:, 1] < -30)[0]]
    static_positions = []
    for id in static_ids:
        static_positions.append(vertices[id])
    handle_ids = [2490]
    handle_positions = [vertices[2490] + np.array((-40, -40, -40))]

    return mesh, static_ids + handle_ids, static_positions + handle_positions


if __name__ == "__main__":
    o3d.utility.set_verbosity_level(o3d.utility.Debug)

    for mesh, constraint_ids, constraint_pos in [
            problem0(), problem1(), problem2()
    ]:
        constraint_ids = np.array(constraint_ids, dtype=np.int32)
        constraint_pos = o3d.utility.Vector3dVector(constraint_pos)
        tic = time.time()
        mesh_prime = mesh.deform_as_rigid_as_possible(
            o3d.utility.IntVector(constraint_ids), constraint_pos, max_iter=50)
        print("deform took {}[s]".format(time.time() - tic))
        mesh_prime.compute_vertex_normals()

        mesh.paint_uniform_color((1, 0, 0))
        handles = o3d.geometry.PointCloud()
        handles.points = constraint_pos
        handles.paint_uniform_color((0, 1, 0))
        o3d.visualization.draw_geometries([mesh, mesh_prime, handles])

    o3d.utility.set_verbosity_level(o3d.utility.Info)

triangle_mesh_filtering_average.py

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from numpy.random.mtrand import laplace
import open3d as o3d
import numpy as np


def average_filtering():
    # Create noisy mesh.
    knot_mesh = o3d.data.KnotMesh()
    mesh_in = o3d.io.read_triangle_mesh(knot_mesh.path)
    vertices = np.asarray(mesh_in.vertices)
    noise = 5
    vertices += np.random.uniform(0, noise, size=vertices.shape)
    mesh_in.vertices = o3d.utility.Vector3dVector(vertices)
    mesh_in.compute_vertex_normals()
    print("Displaying input mesh ...")
    o3d.visualization.draw_geometries([mesh_in])

    print("Displaying output of average mesh filter after 1 iteration ...")
    mesh_out = mesh_in.filter_smooth_simple(number_of_iterations=1)
    mesh_out.compute_vertex_normals()
    o3d.visualization.draw_geometries([mesh_out])

    print("Displaying output of average mesh filter after 5 iteration ...")
    mesh_out = mesh_in.filter_smooth_simple(number_of_iterations=5)
    mesh_out.compute_vertex_normals()
    o3d.visualization.draw_geometries([mesh_out])


def laplace_filtering():
    # Create noisy mesh.
    knot_mesh = o3d.data.KnotMesh()
    mesh_in = o3d.io.read_triangle_mesh(knot_mesh.path)
    vertices = np.asarray(mesh_in.vertices)
    noise = 5
    vertices += np.random.uniform(0, noise, size=vertices.shape)
    mesh_in.vertices = o3d.utility.Vector3dVector(vertices)
    mesh_in.compute_vertex_normals()
    print("Displaying input mesh ...")
    o3d.visualization.draw_geometries([mesh_in])

    print("Displaying output of Laplace mesh filter after 10 iteration ...")
    mesh_out = mesh_in.filter_smooth_laplacian(number_of_iterations=10)
    mesh_out.compute_vertex_normals()
    o3d.visualization.draw_geometries([mesh_out])

    print("Displaying output of Laplace mesh filter after 50 iteration ...")
    mesh_out = mesh_in.filter_smooth_laplacian(number_of_iterations=50)
    mesh_out.compute_vertex_normals()
    o3d.visualization.draw_geometries([mesh_out])


def taubin_filtering():
    # Create noisy mesh.
    knot_mesh = o3d.data.KnotMesh()
    mesh_in = o3d.io.read_triangle_mesh(knot_mesh.path)
    vertices = np.asarray(mesh_in.vertices)
    noise = 5
    vertices += np.random.uniform(0, noise, size=vertices.shape)
    mesh_in.vertices = o3d.utility.Vector3dVector(vertices)
    mesh_in.compute_vertex_normals()
    print("Displaying input mesh ...")
    o3d.visualization.draw_geometries([mesh_in])

    print("Displaying output of Taubin mesh filter after 10 iteration ...")
    mesh_out = mesh_in.filter_smooth_taubin(number_of_iterations=10)
    mesh_out.compute_vertex_normals()
    o3d.visualization.draw_geometries([mesh_out])

    print("Displaying output of Taubin mesh filter after 100 iteration ...")
    mesh_out = mesh_in.filter_smooth_taubin(number_of_iterations=100)
    mesh_out.compute_vertex_normals()
    o3d.visualization.draw_geometries([mesh_out])


if __name__ == "__main__":
    average_filtering()
    laplace_filtering()
    taubin_filtering()

triangle_mesh_from_point_cloud_alpha_shapes.py

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import open3d as o3d

if __name__ == "__main__":
    bunny = o3d.data.BunnyMesh()
    mesh = o3d.io.read_triangle_mesh(bunny.path)
    mesh.compute_vertex_normals()

    pcd = mesh.sample_points_poisson_disk(750)
    print("Displaying input pointcloud ...")
    o3d.visualization.draw_geometries([pcd])
    alpha = 0.03
    print(f"alpha={alpha:.3f}")
    print('Running alpha shapes surface reconstruction ...')
    mesh = o3d.geometry.TriangleMesh.create_from_point_cloud_alpha_shape(
        pcd, alpha)
    mesh.compute_triangle_normals(normalized=True)
    print("Displaying reconstructed mesh ...")
    o3d.visualization.draw_geometries([mesh], mesh_show_back_face=True)

triangle_mesh_from_point_cloud_ball_pivoting.py

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import open3d as o3d

if __name__ == "__main__":
    bunny = o3d.data.BunnyMesh()
    gt_mesh = o3d.io.read_triangle_mesh(bunny.path)
    gt_mesh.compute_vertex_normals()

    pcd = gt_mesh.sample_points_poisson_disk(3000)
    print("Displaying input pointcloud ...")
    o3d.visualization.draw([pcd], point_size=5)

    radii = [0.005, 0.01, 0.02, 0.04]
    print('Running ball pivoting surface reconstruction ...')
    rec_mesh = o3d.geometry.TriangleMesh.create_from_point_cloud_ball_pivoting(
        pcd, o3d.utility.DoubleVector(radii))
    print("Displaying reconstructed mesh ...")
    o3d.visualization.draw([rec_mesh])

triangle_mesh_from_point_cloud_poisson.py

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import open3d as o3d
import numpy as np

if __name__ == "__main__":
    eagle = o3d.data.EaglePointCloud()
    pcd = o3d.io.read_point_cloud(eagle.path)
    R = pcd.get_rotation_matrix_from_xyz((np.pi, -np.pi / 4, 0))
    pcd.rotate(R, center=(0, 0, 0))
    print('Displaying input pointcloud ...')
    o3d.visualization.draw([pcd])

    print('Running Poisson surface reconstruction ...')
    mesh, densities = o3d.geometry.TriangleMesh.create_from_point_cloud_poisson(
        pcd, depth=9)
    print('Displaying reconstructed mesh ...')
    o3d.visualization.draw([mesh])

triangle_mesh_normal_estimation.py

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import open3d as o3d
import numpy as np

if __name__ == "__main__":
    knot_mesh = o3d.data.KnotMesh()
    mesh = o3d.io.read_triangle_mesh(knot_mesh.path)
    print("Displaying mesh without normals ...")
    # Invalidate existing normals.
    mesh.triangle_normals = o3d.utility.Vector3dVector(np.zeros((1, 3)))
    print("normals: \n", np.asarray(mesh.triangle_normals))
    o3d.visualization.draw([mesh])

    print("Computing normals and rendering it ...")
    mesh.compute_vertex_normals()
    print("normals: \n", np.asarray(mesh.triangle_normals))
    o3d.visualization.draw([mesh])

triangle_mesh_properties.py

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import open3d as o3d
import numpy as np
import os
import sys

pyexample_path = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
sys.path.append(pyexample_path)

import open3d_example as o3dex


def check_properties(name, mesh):
    mesh.compute_vertex_normals()

    edge_manifold = mesh.is_edge_manifold(allow_boundary_edges=True)
    edge_manifold_boundary = mesh.is_edge_manifold(allow_boundary_edges=False)
    vertex_manifold = mesh.is_vertex_manifold()
    self_intersecting = mesh.is_self_intersecting()
    watertight = mesh.is_watertight()
    orientable = mesh.is_orientable()

    print(name)
    print(f"  edge_manifold:          {edge_manifold}")
    print(f"  edge_manifold_boundary: {edge_manifold_boundary}")
    print(f"  vertex_manifold:        {vertex_manifold}")
    print(f"  self_intersecting:      {self_intersecting}")
    print(f"  watertight:             {watertight}")
    print(f"  orientable:             {orientable}")

    geoms = [mesh]
    if not edge_manifold:
        edges = mesh.get_non_manifold_edges(allow_boundary_edges=True)
        geoms.append(o3dex.edges_to_lineset(mesh, edges, (1, 0, 0)))
    if not edge_manifold_boundary:
        edges = mesh.get_non_manifold_edges(allow_boundary_edges=False)
        geoms.append(o3dex.edges_to_lineset(mesh, edges, (0, 1, 0)))
    if not vertex_manifold:
        verts = np.asarray(mesh.get_non_manifold_vertices())
        pcl = o3d.geometry.PointCloud(
            points=o3d.utility.Vector3dVector(np.asarray(mesh.vertices)[verts]))
        pcl.paint_uniform_color((0, 0, 1))
        geoms.append(pcl)
    if self_intersecting:
        intersecting_triangles = np.asarray(
            mesh.get_self_intersecting_triangles())
        intersecting_triangles = intersecting_triangles[0:1]
        intersecting_triangles = np.unique(intersecting_triangles)
        print("  # visualize self-intersecting triangles")
        triangles = np.asarray(mesh.triangles)[intersecting_triangles]
        edges = [
            np.vstack((triangles[:, i], triangles[:, j]))
            for i, j in [(0, 1), (1, 2), (2, 0)]
        ]
        edges = np.hstack(edges).T
        edges = o3d.utility.Vector2iVector(edges)
        geoms.append(o3dex.edges_to_lineset(mesh, edges, (1, 0, 1)))
    o3d.visualization.draw_geometries(geoms, mesh_show_back_face=True)


if __name__ == "__main__":
    knot_mesh = o3d.data.KnotMesh()
    mesh = o3d.io.read_triangle_mesh(knot_mesh.path)
    check_properties('KnotMesh', mesh)
    check_properties('Mobius',
                     o3d.geometry.TriangleMesh.create_mobius(twists=1))
    check_properties("non-manifold edge", o3dex.get_non_manifold_edge_mesh())
    check_properties("non-manifold vertex",
                     o3dex.get_non_manifold_vertex_mesh())
    check_properties("open box", o3dex.get_open_box_mesh())
    check_properties("intersecting_boxes", o3dex.get_intersecting_boxes_mesh())

triangle_mesh_sampling.py

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import open3d as o3d

if __name__ == "__main__":
    bunny = o3d.data.BunnyMesh()
    mesh = o3d.io.read_triangle_mesh(bunny.path)
    mesh.compute_vertex_normals()

    print("Displaying input mesh ...")
    o3d.visualization.draw([mesh])

    print("Displaying pointcloud using uniform sampling ...")
    pcd = mesh.sample_points_uniformly(number_of_points=1000)
    o3d.visualization.draw([pcd], point_size=5)

    print("Displaying pointcloud using Poisson disk sampling ...")
    pcd = mesh.sample_points_poisson_disk(number_of_points=1000, init_factor=5)
    o3d.visualization.draw([pcd], point_size=5)

triangle_mesh_simplification_decimation.py

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import open3d as o3d

if __name__ == "__main__":
    bunny = o3d.data.BunnyMesh()
    mesh_in = o3d.io.read_triangle_mesh(bunny.path)
    mesh_in.compute_vertex_normals()

    print("Before Simplification: ", mesh_in)
    o3d.visualization.draw_geometries([mesh_in])

    mesh_smp = mesh_in.simplify_quadric_decimation(
        target_number_of_triangles=6500)
    print("After Simplification target number of triangles = 6500:\n", mesh_smp)
    o3d.visualization.draw_geometries([mesh_smp])

    mesh_smp = mesh_in.simplify_quadric_decimation(
        target_number_of_triangles=1700)
    print("After Simplification target number of triangles = 1700:\n", mesh_smp)
    o3d.visualization.draw_geometries([mesh_smp])

triangle_mesh_simplification_vertex_clustering.py

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import open3d as o3d

if __name__ == "__main__":
    bunny = o3d.data.BunnyMesh()
    mesh_in = o3d.io.read_triangle_mesh(bunny.path)
    mesh_in.compute_vertex_normals()

    print("Before Simplification: ", mesh_in)
    o3d.visualization.draw_geometries([mesh_in])

    voxel_size = max(mesh_in.get_max_bound() - mesh_in.get_min_bound()) / 32
    mesh_smp = mesh_in.simplify_vertex_clustering(
        voxel_size=voxel_size,
        contraction=o3d.geometry.SimplificationContraction.Average)
    print("After Simplification with voxel size =", voxel_size, ":\n", mesh_smp)
    o3d.visualization.draw_geometries([mesh_smp])

    voxel_size = max(mesh_in.get_max_bound() - mesh_in.get_min_bound()) / 16
    mesh_smp = mesh_in.simplify_vertex_clustering(
        voxel_size=voxel_size,
        contraction=o3d.geometry.SimplificationContraction.Average)
    print("After Simplification with voxel size =", voxel_size, ":\n", mesh_smp)
    o3d.visualization.draw_geometries([mesh_smp])

triangle_mesh_subdivision.py

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import open3d as o3d

if __name__ == "__main__":
    knot_mesh = o3d.data.KnotMesh()
    mesh = o3d.io.read_triangle_mesh(knot_mesh.path)
    mesh.compute_vertex_normals()
    print("Before Subdivision: ", mesh)
    print("Displaying input mesh ...")
    o3d.visualization.draw_geometries([mesh], mesh_show_wireframe=True)
    mesh = mesh.subdivide_loop(number_of_iterations=1)
    print("After Subdivision: ", mesh)
    print("Displaying subdivided mesh ...")
    o3d.visualization.draw_geometries([mesh], mesh_show_wireframe=True)

triangle_mesh_transformation.py

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import open3d as o3d
import numpy as np
import copy


def translate():
    mesh = o3d.geometry.TriangleMesh.create_coordinate_frame()
    mesh_tx = copy.deepcopy(mesh).translate((1.3, 0, 0))
    mesh_ty = copy.deepcopy(mesh).translate((0, 1.3, 0))
    print('Displaying original and translated geometries ...')
    o3d.visualization.draw([{
        "name": "Original Geometry",
        "geometry": mesh
    }, {
        "name": "Translated (in X) Geometry",
        "geometry": mesh_tx
    }, {
        "name": "Translated (in Y) Geometry",
        "geometry": mesh_ty
    }],
                           show_ui=True)


def rotate():
    mesh = o3d.geometry.TriangleMesh.create_coordinate_frame()
    mesh_r = copy.deepcopy(mesh)
    R = mesh.get_rotation_matrix_from_xyz((np.pi / 2, 0, np.pi / 4))
    mesh_r.rotate(R, center=(0, 0, 0))
    print('Displaying original and rotated geometries ...')
    o3d.visualization.draw([{
        "name": "Original Geometry",
        "geometry": mesh
    }, {
        "name": "Rotated Geometry",
        "geometry": mesh_r
    }],
                           show_ui=True)


def scale():
    mesh = o3d.geometry.TriangleMesh.create_coordinate_frame()
    mesh_s = copy.deepcopy(mesh).translate((2, 0, 0))
    mesh_s.scale(0.5, center=mesh_s.get_center())
    print('Displaying original and scaled geometries ...')
    o3d.visualization.draw([{
        "name": "Original Geometry",
        "geometry": mesh
    }, {
        "name": "Scaled Geometry",
        "geometry": mesh_s
    }],
                           show_ui=True)


def transform():
    mesh = o3d.geometry.TriangleMesh.create_coordinate_frame()
    T = np.eye(4)
    T[:3, :3] = mesh.get_rotation_matrix_from_xyz((0, np.pi / 3, np.pi / 2))
    T[0, 3] = 1
    T[1, 3] = 1.3
    print(T)
    mesh_t = copy.deepcopy(mesh).transform(T)
    print('Displaying original and transformed geometries ...')
    o3d.visualization.draw([{
        "name": "Original Geometry",
        "geometry": mesh
    }, {
        "name": "Transformed Geometry",
        "geometry": mesh_t
    }],
                           show_ui=True)


if __name__ == "__main__":

    translate()
    rotate()
    scale()
    transform()

triangle_mesh_with_numpy.py

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import open3d as o3d
import numpy as np

if __name__ == "__main__":
    # Read a mesh and get its data as numpy arrays.
    knot_mesh = o3d.data.KnotMesh()
    mesh = o3d.io.read_triangle_mesh(knot_mesh.path)
    mesh.paint_uniform_color([0.5, 0.1, 0.3])
    print('Vertices:')
    print(np.asarray(mesh.vertices))
    print('Vertex Colors:')
    print(np.asarray(mesh.vertex_colors))
    print('Vertex Normals:')
    print(np.asarray(mesh.vertex_normals))
    print('Triangles:')
    print(np.asarray(mesh.triangles))
    print('Triangle Normals:')
    print(np.asarray(mesh.triangle_normals))
    print("Displaying mesh ...")
    print(mesh)
    o3d.visualization.draw([mesh])

    # Create a mesh using numpy arrays with random colors.
    N = 5
    vertices = o3d.utility.Vector3dVector(
        np.array([[0, 0, 0], [1, 0, 0], [1, 0, 1], [0, 0, 1], [0.5, 0.5, 0.5]]))
    triangles = o3d.utility.Vector3iVector(
        np.array([[0, 1, 2], [0, 2, 3], [0, 4, 1], [1, 4, 2], [2, 4, 3],
                  [3, 4, 0]]))
    mesh_np = o3d.geometry.TriangleMesh(vertices, triangles)
    mesh_np.vertex_colors = o3d.utility.Vector3dVector(
        np.random.uniform(0, 1, size=(N, 3)))
    mesh_np.compute_vertex_normals()
    print(np.asarray(mesh_np.triangle_normals))
    print("Displaying mesh made using numpy ...")
    o3d.visualization.draw_geometries([mesh_np])