Thanks for implementing the feature. I have been having some difficulties in reproducing the notebook https://plot.ly/python/3d-cone/ or tried to use ploly.graph_objs.Cone.

With iplot it shows a plot with 2D layout like scatter while 3d is expected.
With plot to save to a file and open it with chrome. It shows an empty grid.

Also "Edit in Chart Studio" button does not work for me in either case.

I have verified that I am using 3.0.0 version, and the html files says plotly.js 1.38.3. I have been mostly following the notebook except for using plotly.offline.plot and iplot instead.