If aLine3DCollection is initialized from iterable arguments, it will be rendered initially, however will disappear upon rotation.
Here's code that reproduces the issue:

import matplotlib.pyplot as pltfrom mpl_toolkits import mplot3dfig = plt.figure()ax = fig.add_subplot((111),  projection='3d')ax.scatter((1, 2), (1, 2), (1, 2))lines = iter([((1, 1, 1), (2, 2, 2))])ax.add_collection(mplot3d.art3d.Line3DCollection(lines))

This shows a plot with two dots an a line connecting them. However when viewpoint is changed using GUI, the line disappears. I suspect the same behavior applies to any other 3D collection.