Fix pathpatch3d_demo.py on Python 3

[cgohlke]

No description provided.

[pelson]

Isn't this needed to register the 3d projection?

[cgohlke]

It's not used anywhere in the file. Does the import have a side effect?

[pelson]

From memory yes. I think it registers the projection with matplotlib. Presumably the code still runs as there are other 3d imports, but this particular import should remain and should be explicitly commented as to why it is there.

[cgohlke]

OK, Thanks. I'll work on the remaining issues tomorrow.

[WeatherGod]

Yes, it is needed there. By importing Axes3D, the Axes3D class gets registered with the rest of matplotlib and it allows for more seamless integration with the rest of mpl. This is fully documented in the mplot3d documentation.

[WeatherGod]

But, yes, because of the other mplot3d imports there, removing that line still works, but I would rather keep everything consistent with the documentation.

[pelson]

Out of interest, what was broken in Python 3 with this example?

[cgohlke]

  File "pathpatch3d_demo.py", line 9
    def text3d(ax, (x, y, z), s, zdir="z", size=None, angle=0, usetex=False,
                   ^
SyntaxError: invalid syntax

[WeatherGod]

heh, never knew it was possible to do that. Looks like 3.0 removed that feature. Good thing I never learned that hideous syntax.