Bug summary

Hello,

Passing the mouse on the figure when plot has been generated with 'ortho' projection 3d mode and specific azimuthal and elevation angles returns the following message :

C:....\lib\site-packages\mpl_toolkits\mplot3d\proj3d.py:25: RuntimeWarning: invalid value encountered in double_scalars
u = (x01x21 + y01y21) / (x21¨¨2 + y21¨¨2)

Could you please investigate this ?
thanks,
Patrick

Code for reproduction

import matplotlib.pyplot as plt

fig, ax = plt.subplots(subplot_kw={'projection': '3d'})
ax.scatter(0, 0)
ax.set_proj_type('ortho')
ax.view_init(azim=-90, elev=90)
plt.show()

Actual outcome

C:....\lib\site-packages\mpl_toolkits\mplot3d\proj3d.py:25: RuntimeWarning: invalid value encountered in double_scalars
u = (x01x21 + y01y21) / (x212 + y212)

Expected outcome

No RuntimeWarning message

Additional information

No response

Operating system

Windows

Matplotlib Version

3.4.2

Matplotlib Backend

No response

Python version

3.7.7

Jupyter version

No response

Installation

pip