python vtk 管过滤器返回空数组

Question

我正在尝试使用 vtkTubeFilter 对象围绕点线获取管。 由于我有自己的专用渲染代码，我想直接获取顶点，而不仅仅是过滤器对象。 我正在尝试使用以下方法在numpy数组和 VTK 数据结构之间进行转换

field = vtk.vtkFieldData()
field.AddArray(vtk_numpy_support.numpy_to_vtk(center_line))

但最后似乎代码只是返回一个空数组。

我必须以某种方式执行过滤器吗？ 或者也许把点放入数据结构的方法是错误的？ 我之前没有对VTK做过任何事情，所以我对过滤器管道结构还不是很熟悉。 任何指向正确方向的指针将不胜感激！

下面是重现问题的完整代码：

import numpy as np
import vtk
from vtk.util import numpy_support as vtk_numpy_support

n = 6
radius = 5.0
center_line = np.array([[-36.78,  19.78, -37.82],
                        [37.65,  20.04, -35.89],
                        [-38.85,  20.39, -32.84],
                        [-39.85,  20.68, -29.65],
                        [-40.57,  20.89, -26.37],
                        [-40.98,  21.  , -23.02],
                        [-41.05,  21.01, -19.67],
                        [-40.78,  20.93, -16.34],
                        [-40.21,  20.75, -13.07],
                        [-39.33,  20.48,  -9.86],
                        [-38.14,  20.12,  -6.72],
                        [-36.66,  19.67,  -3.68],
                        [-34.95,  19.15,  -0.75]])
tube_filter = vtk.vtkTubeFilter()
tube_filter.SetNumberOfSides(n)
tube_filter.SetCapping(True)
tube_filter.SetRadius(radius)
field = vtk.vtkFieldData()
field.AddArray(vtk_numpy_support.numpy_to_vtk(center_line))
data_obj = vtk.vtkDataObject()
data_obj.SetFieldData(field)
tube_filter.SetInputData(data_obj)
vertices = vtk_numpy_support.vtk_to_numpy(tube_filter.GetOutput().GetVerts().GetData())

print(vertices)

输出：

/home/user/anaconda3/lib/python3.6/site-packages/vtk/util/numpy_support.py:137: FutureWarning: Conversion of the second argument of issubdtype from `complex` to `np.complexfloating` is deprecated. In future, it will be treated as `np.complex128 == np.dtype(complex).type`.
  assert not numpy.issubdtype(z.dtype, complex), \
[]

PS：我也不太确定为什么将数组解释为复杂类型。 在我的调试器中，它显示为正常的float64数字。

Answer 1

使用vtkplotter ：

from vtkplotter import Tube

center_line = [ [-36.78,  19.78, -37.82],
                [-37.65,  20.04, -35.89],
                [-38.85,  20.39, -32.84],
                [-39.85,  20.68, -29.65],
                [-40.57,  20.89, -26.37],
                [-40.98,  21.  , -23.02],
                [-41.05,  21.01, -19.67],
                [-40.78,  20.93, -16.34],
                [-40.21,  20.75, -13.07],
                [-39.33,  20.48,  -9.86],
                [-38.14,  20.12,  -6.72],
                [-36.66,  19.67,  -3.68],
                [-34.95,  19.15,  -0.75] ]

t = Tube(center_line, r=5, cap=True, res=6)

print(t.points()) # numpy array

t.show()