【Python-Open3D学习笔记】005Mesh相关方法

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 = 0volume = 0try: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, volumeexcept Exception as e:print(f"Error occurred: {str(e)}")return surface_area, volume