vedo, formerly known as vtkplotter

[gdmcbain]

As noted in #44, matplotlib distorts three-dimensional views uncontrollably. Some very nice plots were added to #357 using vtkplotter. It might be a worthwhile addition to skfem.visuals #286. (I haven't looked at the licence or portability.)

[kinnala]

License seems to be MIT. I don't oppose this, the plots look great. I'll try to get it working on my Python setup and try it out.

[gdmcbain]

A quick experiment went well.

On a laptop running Microsoft Windows 10

pip install vtkplotter

Then after having run ex32.py from #342, run

from vtkplotter import Plotter

vp = Plotter()
vp.load('ex32.vtk')
vp.show()

This pops up a 'Visualization Toolkit Win32OpenGL' showing a green triangulated ellipsoid which can be rotated, translated, and zoomed with the mouse.

• Hit 'h' in this window to display help back in the terminal.
• Hit '4' to cycle through scalars to colour by; here twice for pressure.
• Hit 's' to save screenshot.png.

This does nicely show the p ~xy pattern expected from creeping convection in a horizontally heated ellipsoid.

I assume this could be scripted, once I read the docs.

[gdmcbain]

To generate a PNG rather than a window,

from vtkplotter import Plotter, screenshot

vp = Plotter(offscreen=True)
...
screenshot('ex32.png')

See marcomusy/vedo#55.

That saves the PNG without throwing up a window; however, it doesn't colour by pressure. The answer to that might be in marcomusy/vedo#131.

[gdmcbain]

Here we go:

from vtkplotter import Plotter, screenshot

Plotter(offscreen=True).load("ex32.vtk").pointColors("pressure").show()
screenshot("ex32.png")

[gdmcbain]

I'd deferred this as it wasn't working on my Ubuntu 19.10 desktop (something about nvidia nouveau); as mentioned the previous work had been done under Microsoft Windows 10.

Yesterday I updated the desktop to Ubuntu 20.04 LTS and it's working fine. Here's a recipe.

• conda 4.8.3 # from Miniconda3-latest-Linux-x86_64.sh
• python=3.7 in a conda create # gives Python 3.7.7
• conda install vtk
• pip install vtkplotter

[kinnala]

I've been encountering issues trying to run this in a docker container, I'm only developing inside containers nowadays.

I think I have to next try it out in a Ubuntu 20.04 virtual machine.