Slicing for 3D volume does not work

[PetrDvoracek]

Versions

python 3.8.12
ipyvolume 0.6.0a10

Problem

I followed the tutorial to create slices in 3d volume https://ipyvolume.readthedocs.io/en/latest/examples/slice.html. First I show show the volume with

import ipyvolume as ipv
fig = ipv.figure()
scatter = ipv.examples.gaussian(show=False)
ipv.show()

then I try to add the slice planes with

plane = ipv.plot_plane("z");

but I got an error instead

---------------------------------------------------------------------------
UnboundLocalError                         Traceback (most recent call last)
Input In [71], in <cell line: 1>()
----> 1 plane = ipv.plot_plane("x")

File ~/anaconda3/envs/mozek/lib/python3.8/site-packages/ipyvolume/pylab.py:1113, in plot_plane(where, texture)
   1111     u = [0., 1., 1., 0.]
   1112     v = [0., 0., 1., 1.]
-> 1113 mesh = plot_trisurf(x, y, z, triangles, texture=texture, u=u, v=v)
   1114 return mesh

UnboundLocalError: local variable 'x' referenced before assignment

Do you have any idea why the slicing tutorial is not reproducible in my environment?

[JBartrand]

It appears there was a major update to the plot_plane function such that the 'where' options were changed from {'x', 'y','z'} to {'front', 'back', 'left', 'right', 'top', 'bottom'}. If you change the plot_plane argument to "top", you will solve this error, but other errors will arise.