Plotly.js: Support for 'fill' attributes in 'scatter3d'

[cpsievert]

Originally requested here https://github.com/ropensci/plotly/issues/1179

[etpinard]

There's this thing: https://plot.ly/python/3d-filled-line-plots/ in the python docs.

Could be a nice feature for the R API? :stuck_out_tongue:

But yeah, why not, it would be nice to fill attributes that behave more closely to what 2d axes support.

[alexcjohnson]

FWIW that python example has a bug - looks like the fill is perhaps it's making a convex hull rather than just filling below the line? I haven't looked in enough detail to know whether this is a problem on the python or plotly.js side.

[jonmmease]

Reported again in https://github.com/plotly/plotly.py/issues/1206

I don't think this is a Python specific issue. The surface fill here is being turned on by the scatter3d.surfaceaxis and scatter3d.surfacecolor properties.

The docs for surfaceaxis are

If "-1", the scatter points are not fill with a surface If 0,
1, 2, the scatter points are filled with a Delaunay surface
about the x, y, z respectively.

So I think what's happening here is that Delaunay triangularization doesn't take into account the order of the points and so when all of the points are on a plane you end up with a convex hull. And so it's not really meaningful to compare it with the line. So perhaps we should take down this documentation example.

I think what this Python example wants is the 3d fill option from the feature request.

[MdoubleDash]

FWIW, I have seen this bug in R as well. Posted an issue in documentation, then realized there is one already opened here, which is the place it should be. I just included the reproducible example in my thread.

[Zaesh]

Has anyone found a fix for that issue yet?