TriangleMesh相关方法

1. 查看mesh三角形面信息

def view_hull_triangles(hull: o3d.geometry.TriangleMesh):
    """
    查看mesh三角形面信息（顶点索引、顶点坐标）
    :param hull:
    :return:
    """
    # 获取三角形的顶点索引
    triangles = np.asarray(hull.triangles)  # 每个三角形由三个顶点的索引组成
    # 获取顶点坐标
    vertices = np.asarray(hull.vertices)  # 所有顶点的坐标

    print(f"总共有 {len(triangles)} 个三角形面")
    for i, triangle in enumerate(triangles):
        print(f"三角形 {i + 1}: 顶点索引 {triangle}, 顶点坐标:")
        for idx in triangle:
            print(f"  顶点 {idx}: {vertices[idx]}")

    return triangles, vertices

2. 可视化三角形

def highlight_triangle(hull: o3d.geometry.TriangleMesh, triangle_idx: int):
    """
    可视化单个三角形
    :param hull:
    :param triangle_idx:
    :return:
    """
    # 获取三角形索引
    triangles = np.asarray(hull.triangles)
    vertices = np.asarray(hull.vertices)

    # 获取特定三角形的顶点
    triangle = triangles[triangle_idx]
    triangle_vertices = vertices[triangle]

    # 创建一个新点云，表示高亮的三角形
    highlight = o3d.geometry.TriangleMesh()
    highlight.vertices = o3d.utility.Vector3dVector(triangle_vertices)
    highlight.triangles = o3d.utility.Vector3iVector([[0, 1, 2]])
    highlight.paint_uniform_color([1, 0, 0])  # 高亮颜色：红色

    # 绘制原始凸包和高亮三角形
    o3d.visualization.draw_geometries([hull, highlight], window_name="Highlight Triangle")

def highlight_all_triangles(hull: o3d.geometry.TriangleMesh, show=False):
    """
    可视化所有三角形
    :param hull:
    :param show: 是否直接显示
    :return:
    """
    # 获取三角形索引和顶点坐标
    triangles = np.asarray(hull.triangles)
    vertices = np.asarray(hull.vertices)

    # 创建一个新三角网格，用于高亮显示
    highlight_mesh = o3d.geometry.TriangleMesh()

    # 存储所有高亮的顶点和三角形
    all_highlighted_vertices = []
    all_highlighted_triangles = []
    colors = []

    for i, triangle in enumerate(triangles):
        # 获取三角形顶点
        triangle_vertices = vertices[triangle]

        # 偏移索引（因为顶点需要连续编号）
        base_index = len(all_highlighted_vertices)

        # 添加当前三角形的顶点
        all_highlighted_vertices.extend(triangle_vertices)

        # 添加当前三角形的索引（注意偏移）
        all_highlighted_triangles.append([base_index, base_index + 1, base_index + 2])

        # 为每个三角形分配随机颜色
        random_color = np.random.rand(3)  # RGB 随机颜色
        colors.append(random_color)

    # 设置高亮网格的顶点、三角形和颜色
    highlight_mesh.vertices = o3d.utility.Vector3dVector(all_highlighted_vertices)
    highlight_mesh.triangles = o3d.utility.Vector3iVector(all_highlighted_triangles)
    highlight_mesh.vertex_colors = o3d.utility.Vector3dVector(
        np.repeat(colors, 3, axis=0)  # 每个顶点与其三角形共享同样的颜色
    )

    # 绘制原始凸包和高亮网格
    # o3d.visualization.draw_geometries([hull, highlight_mesh], window_name="Highlight All Triangles")
    if show:
        o3d.visualization.draw_geometries([highlight_mesh], window_name="Highlight All Triangles")
    return highlight_mesh

显示效果：

3. 上采样

def upsample_by_mesh(mesh: o3d.geometry.TriangleMesh, number_of_points: int = 10000):
    """
    通过mesh进行上采样
    :param mesh:
    :param number_of_points:
    :return:
    """
    dense_pcd = mesh.sample_points_uniformly(number_of_points=number_of_points)
    return dense_pcd

原始数据：

上采样后：

4. 计算mesh形成的面积和体积

def calculate_hull_metrics(hull: o3d.geometry.TriangleMesh):
    surface_area = 0
    volume = 0
    try:
        if not hull.is_watertight():
            # print("网格不是水密的！尝试简化修复")
            hull = hull.simplify_quadric_decimation(target_number_of_triangles=1000)

        # print("网格是水密的！")
        # 计算表面积
        surface_area = hull.get_surface_area()
        # 计算体积
        volume = hull.get_volume()
        return surface_area, volume
    except Exception as e:
        print(f"Error occurred: {str(e)}")
        return surface_area, volume