一、效果

1.1.流形曲面

1.2.离散网格

在三维空间中的四个三角形

二、完整代码

import vtkmodules.all as vtk
import numpy as np

# 0.构造数据
vs = np.array([[-1, 1, -1],    # 顶点坐标
               [-1, 0, 0],
               [-1, -1, -1],
               [0, 0.5, 0],
               [0, -0.5, 0],
               [0.5, 0, -1]], dtype=np.float32)  # 0.5 -0.5
faces = np.array([[4, 1, 3], [4, 1, 2], [0, 3, 1], [3, 5, 4]], dtype=np.int16)  # 三角网格
c = np.array([[1, 1, 1], [1, 0, 0], [0, 1, 0], [0, 0, 1]]) * 255      # 颜色

# 1.vtk创建PolyData
points = vtk.vtkPoints()          # 顶点
for v in vs:
    points.InsertNextPoint(v)
polys = vtk.vtkCellArray()        # 三角
for f in faces:
    polys.InsertNextCell(3, f)
cellColor = vtk.vtkUnsignedCharArray()    # 存储颜色
cellColor.SetNumberOfComponents(3)        # RGB三通道
for tmp in c:
    cellColor.InsertNextTuple(tmp)
cube = vtk.vtkPolyData()                  # 分别添加到PolyData
cube.SetPoints(points)
cube.SetPolys(polys)
cube.GetCellData().SetScalars(cellColor)

# 1.5细分
l = vtk.vtkLinearSubdivisionFilter()      # 先linear
l.SetInputData(cube)
l.SetNumberOfSubdivisions(1)
l.Update()

loop = vtk.vtkLoopSubdivisionFilter()     # 后loop
loop.SetInputConnection(l.GetOutputPort())
loop.SetNumberOfSubdivisions(5)
loop.Update()

# 2.创建Mapper
mapper = vtk.vtkPolyDataMapper()
mapper.SetColorModeToDefault()
# mapper.SetInputData(cube)                        # 离散网格
mapper.SetInputConnection(loop.GetOutputPort())    # 细分之后的 近似曲面

# 3.创建Actor
actor = vtk.vtkActor()
actor.SetMapper(mapper)
#actor.GetProperty().SetEdgeColor(0, 0, 0)
#actor.GetProperty().SetEdgeVisibility(1)    # 显示边

# 4.创建Renderer
renderer = vtk.vtkRenderer()
renderer.SetBackground(1, 1, 1)    # 背景白色
renderer.AddActor(actor)           # 将actor加入
renderer.ResetCamera()             # 调整显示

# 5.渲染窗口
renWin = vtk.vtkRenderWindow()
renWin.AddRenderer(renderer)
renWin.Render()

# 6.交互
renWinInteractor = vtk.vtkRenderWindowInteractor()
renWinInteractor.SetRenderWindow(renWin)
renWinInteractor.SetInteractorStyle(vtk.vtkInteractorStyleTrackballCamera())
renWinInteractor.Start()

参考链接

• https://zhuanlan.zhihu.com/p/115081182 (可视化：第一个VTK例子)
• https://zhuanlan.zhihu.com/p/336743251 (VTK图像处理（二）–vtkPolyData数据处理)
• https://blog.csdn.net/shenziheng1/article/details/54836856 (VTK修炼之道45：图形进阶_vtkPolyData属性数据)