exportWindow() with volumetric data doesn't work as expected?

Hello,

I’m trying to export the vtkplotter scene to .x3d file to inspect in the browser, in the way similar to the export_x3d.py example: https://github.com/marcomusy/vtkplotter-examples/blob/master/vtkplotter_examples/other/export_x3d.py

However, seems like it is not working as expected while trying to export the scene with volumetric data (e.g. MIP rendering style). Here is the code snippet inspired by export_x3d.py:

from vtkplotter import *

e = load(datadir+'embryo.tif')
e.mode(1)
e.color("gray")

t = Text(__doc__, pos=[3000., 2000., 4723], s=150, c='w', depth=0.1)
show(t, e)

exportWindow('embryo.x3d')

Volumetric data is properly visualized in vtkplotter window, but it seems like there is only a text in embryo.x3d file after opening embryo.html file in the browser. Moreover, while trying to visualize and export volumetric data only (i.e. show(e) instead of show(t, e)) the following error occurs:

ERROR: In /work/standalone-x64-build/VTK-source/IO/Export/vtkX3DExporter.cxx, line 138
vtkX3DExporter (0x33fb5d0): no actors found for writing X3D file.

Any help is appreciated. Thanks!

[kemo993]

Thank you @marcomusy – this really helped me navigate the alternatives.

[marcomusy]

Hi, I strongly suspect that the underlying vtkX3DExporter class is not able to export volumes. One possibility is to exploit k3d interoperability and do something like this, which generates a html document:

import k3d
import numpy as np
from vtkplotter import load, datadir

vol = load(datadir+'embryo.tif')

kx, ky, kz = vol.dimensions()
arr = vol.getPointArray()
kimage = arr.reshape(-1, ky, kx).astype(np.float32)

plot = k3d.plot()
kvol = k3d.volume(kimage, alpha_coef=20, bounds=vol.bounds())
plot += kvol
with open('page.html','w') as fp:
    fp.write(plot.get_snapshot())