Bug report

Bug summary

I found multiple issues ofautoscale_view forLine3DCollection that

1. autoscale_view takes no effect for plots withLine3DCollection.
2. autoscale_view even breaks the original bounds and forces it to be a unit cube if it is used withax.set_autoscale_on(True).

This is reported from the downstream issuesympy/sympy#19106

Code for reproduction

importnumpyasnpimportmatplotlib.pyplotaspltfrommpl_toolkits.mplot3dimportAxes3Dfrommpl_toolkits.mplot3d.art3dimportLine3DCollectionz=np.linspace(-4*np.pi,4*np.pi,100)x=np.sin(z)y=np.cos(z)segments= []foriinrange(len(z)-1):z0,x0,y0=z[i],x[i],y[i]z1,x1,y1=z[i+1],x[i+1],y[i+1]segments.append([(x0,y0,z0), (x1,y1,z1)])collection=Line3DCollection(segments)fig=plt.figure()ax=fig.gca(projection='3d')ax.add_collection3d(collection)ax.set_xlim3d(-1,1)ax.set_ylim3d(-1,1)ax.set_zlim3d(-4*np.pi,4*np.pi)ax.set_autoscale_on(True)ax.autoscale_view()plt.show()

Actual outcome

Expected outcome

Matplotlib version

• Operating system:
• Matplotlib version: 3.2
• Matplotlib backend (print(matplotlib.get_backend())): module://ipykernel.pylab.backend_inline
• Python version: 3.7.7
• Jupyter version (if applicable):
• Other libraries: