Problem

Currently we position the 3D axis spines and panes such that they appear along the back face of the view volume. This can be thought of as viewing only a single quadrant of the coordinate frame: (image from here)

There are some use cases where it would be useful to be able to instead position the axis spines in the middle of the world volume, similar as to the 2D example here: https://stackoverflow.com/questions/31556446/how-to-draw-axis-in-the-middle-of-the-figure

A 3D rough example here (but replace the black arrows with spines): https://stackoverflow.com/questions/54820671/switching-the-location-of-x-and-y-axes-for-a-3d-plot

I think this would look rather messy with the view panes enabled, but if the panes are hidden just the axes are shown then I think it could be quite useful. I also think that this could be useful for "slicing" the view volume and reading off the hover coordinates when mousing over the plot.

Requests for this functionality:

• https://discourse.matplotlib.org/t/feature-request-3d-axes-positioning-to-origin/25570
• https://stackoverflow.com/questions/50493036/changing-the-position-of-an-axis-on-a-axes3d

Proposed solution

No response