使用Plotly Mesh3D绘制OFF文件3D网格结果与原模型不符问题求助

你已经正确读取了OFF文件的顶点和面数据，但调用Mesh3d时没有传入定义网格拓扑的面索引参数。Plotly的Mesh3d在仅传入顶点坐标时，会自动对顶点执行Delaunay三角剖分生成面，和OFF文件中预先定义的原始面结构完全不符，因此输出的可视化结果错误。

将读取到的faces数组拆分为Mesh3d要求的三个面索引参数i、j、k，分别对应每个三角面的三个顶点索引，初始化Mesh3d时一并传入即可。

import plotly.graph_objects as go
import numpy as np

# loading the mesh and getting the vertices
def ExtractRawData(filepath):
    # read the file path
    with open(filepath) as file:
        if 'OFF' != file.readline().strip():
            raise Exception('Not a valid OFF header')
        n_verts, n_faces, n_dontknow = tuple([int(s) for s in file.readline().strip().split(' ')])
        verts = [[float(s) for s in file.readline().strip().split(' ')] for i_vert in range(n_verts)]
        faces = [[int(s) for s in file.readline().strip().split(' ')][1:] for i_face in range(n_faces)]
        return np.array(verts), np.array(faces)

# extracting the vertices from the off file 
verts, faces = ExtractRawData('Turbine blade.off')
# getting the x, y and z coordinates from the vertices
x = verts[:,0]
y = verts[:,1]
z = verts[:,2]
# 拆分面索引为i、j、k参数
i = faces[:, 0]
j = faces[:, 1]
k = faces[:, 2]

# 传入面索引参数绘制网格
fig = go.Figure(data=[go.Mesh3d(x=x, y=y, z=z, i=i, j=j, k=k)])
fig.show()

内容的提问来源于stack exchange，提问作者Aman Savaria