将 mayavi mlab.contour3d 绘图转换为 vtkPolyData [英] Convert mayavi mlab.contour3d plot to vtkPolyData

问题描述

我正在尝试从 mlab.contour3d 图中获取三角化的 vtkPolyData.我正在使用 mayavi 因为它似乎是获得 最小表面 的最快方法a> 正确三角化.我需要它作为 vtkPolyData 因为我想将它保存为 .stl 文件.

I am trying to get the triangulated vtkPolyData from a mlab.contour3d plot. I am using mayavi because it seems to be the fastest way to get minimal surfaces triangulated properly. I need it as vtkPolyData because I want to save it as an .stl file.

这是我的代码的 MWE:

Here is a MWE of my code:

import numpy as np
from mayavi import mlab

def fun(x, y, z):
    return np.cos(x) + np.cos(y) + np.cos(z)

x, y, z = np.mgrid[-1:1:100j, -1:1:100j, -1:1:100j]
contour = mlab.contour3d(x, y, z, fun)
mlab.show()

然后我从 mayavi 得到的是一个已经使用 VTK(或 tvtk)进行三角测量和显示的表面，所以它应该是可以从那里获得 vtkPolyData.但到目前为止我发现的唯一方法是使用 mlab.savefig(test.obj) 导出 .obj 文件(这很糟糕，因为每次 mayavi UI 打开)并使用 vtkOBJReader 再次导入该文件，这为我提供了我想要的 vtkPolyData.

What I get then from mayavi is a surface that is already triangulated and displayed using VTK (or tvtk), so it should be possible to get the vtkPolyData from there. But the only way I found so far is to use mlab.savefig(test.obj) to export an .obj-file (which is bad, because it takes time to save the file everytime the mayavi UI opens) and import that file again using vtkOBJReader, which gives me the vtkPolyData I want.

有人知道更直接的方法吗?

Does anyone know a more straight-forward way to do this?

为了进一步澄清我的问题:我可以从可视化中访问数据，例如使用 mayavi.tools.pipeline.get_vtk_src()，但它以 vtkImageData 的形式出现.如果有人知道将其转换为 vtkPolyData 的方法，那也是一个解决方案.

edit: To clarify my problem a bit more: I can access the data from the visualization e.g. with mayavi.tools.pipeline.get_vtk_src(), but it comes in form of vtkImageData. If anyone knows a way to convert that to vtkPolyData, that would also be a solution.

推荐答案

很巧，我找到了解决方案.

By total coincidence I found a solution.

import numpy as np
from mayavi import mlab

def fun(x, y, z):
    return np.cos(x) + np.cos(y) + np.cos(z)

x, y, z = np.mgrid[-1:1:100j, -1:1:100j, -1:1:100j]
contour = mlab.contour3d(x, y, z, fun)
actor = contour.actor.actors[0]
polydata = tvtk.to_vtk(actor.mapper.input)  # solution
mlab.show()

诀窍似乎是从管道访问映射器，它是一个 PolyDataMapper.然后我只使用 tvtk.to_vtk() 函数，这样我就可以继续使用 vtk ，我更喜欢 tvtk ，至少现在是这样.

The trick seems to be to access the mapper from the pipeline, which is a PolyDataMapper. Then I just use the tvtk.to_vtk() function so that I can continue with vtk which I prefer over tvtk, at least for now.

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