svg do not show isoline (at least in multi plots)

[doutriaux1]

import cdms2, vcs
f = cdms2.open(vcs.sample_data + "/clt.nc")
s = f("clt")
x = vcs.init()
x.plot(s,"default", "isofill")
x.plot(s,"default", "isoline")
x.svg("isofill_isoline")

[doutriaux1]

png works

[scottwittenburg]

I'll take a look, but svg support on the VTK side is not great in general. I did think svg export of a basic isoline worked though.

[doutriaux1]

actually no 😭

[scottwittenburg]

I was wrong. On the VTK side we don't support polydata cells of type POLYLINE when exporting to SVG, and that's the kind of cell we have for isoline. It might not be too bad to add this support it to VTK, but it will require some experimentation, development, debugging over there first. If we're lucky it could be a day's effort or so, unless we hit a snag.

[scottwittenburg]

Actually, it might be a pretty easy fix on the VTK side. I just created an MR which seems to work for me in some simple testing, let's see how it does on the VTK dashboard.

[scottwittenburg]

It's looking good so far. There are a few test failures but they seem unrelated, and at least one machine tested the svg export functionality, and those tests passed on that machine.

So I could update one of those VTK tests to exercise this new functionality, and then that topic would be pretty easy to get reviewed and merged I think. We will still face the problem that we can't take VTK master yet, due to the "weak-linking against python bug" keeping us from getting a working build on OSX py3.

[doutriaux1]

@muryanto1 the issue was with svg files. You sent me png files. So I can't confirm it's fixed.