Changing point of view in 3D plots in Matplotlib

Question

I am trying to change the view of a 3D plot as if I'm standing at the red point looking in the direction of the green line. Setting the azimuth angle of the view to be equal to the slope takes care of the direction. However, zooming to the red point level is an issue. I know that ax.dist is the key, but I don't know how to properly use it. If the red point is not in the middle of the plot, it will disappear from the view after a certain level of zooming.

and here's the code

import numpy as np  
import matplotlib.pyplot as plt  

fig = plt.figure()  
ax = fig.gca(projection='3d')  

def set_axes_equal(ax):  
    '''Make axes of 3D plot have equal scale so that spheres appear as spheres,
    cubes as cubes, etc..  This is one possible solution to Matplotlib's
    ax.set_aspect('equal') and ax.axis('equal') not working for 3D.

    Input  
      ax: a matplotlib axis, e.g., as output from plt.gca().  
    '''  

    x_limits = ax.get_xlim3d()  
    y_limits = ax.get_ylim3d()  
    z_limits = ax.get_zlim3d()

    x_range = abs(x_limits[1] - x_limits[0])  
    x_middle = np.mean(x_limits)  
    y_range = abs(y_limits[1] - y_limits[0])
    y_middle = np.mean(y_limits)
    z_range = abs(z_limits[1] - z_limits[0])
    z_middle = np.mean(z_limits)

    # The plot bounding box is a sphere in the sense of the infinity
    # norm, hence I call half the max range the plot radius.
    plot_radius = 0.5*max([x_range, y_range, z_range])  

    ax.set_xlim3d([x_middle - plot_radius, x_middle + plot_radius])
    ax.set_ylim3d([y_middle - plot_radius, y_middle + plot_radius])
    ax.set_zlim3d([z_middle - plot_radius, z_middle + plot_radius])  



y1 = range(20)  
x1 = [1] * len(y1)  
x2 = np.array(range(11))
y2 = -x2 + 10
x3 = np.array(range(1, 9))
y3 = x3 * 2
z3 = range(len(x3))
x4 = range(6, 10)
y4 = [12.5] * len(x4)
y5 = range(20)
x5 = [15] * len(y5)  

ax.plot(x1, y1, color = 'y')  
ax.plot(x2, y2, color = 'g')
ax.plot([5], [5], [0], 'or', markersize = 4)
ax.plot(x3, y3, z3, color = 'm')
ax.plot(x4, y4, color = 'b')
ax.plot(x5, y5, color = 'c')


set_axes_equal(ax)  
ax.set_xlabel("x")  
ax.set_ylabel("y")  
azi = np.degrees(np.arctan((x2[-1]-x2[0])/(y2[-1]-y2[0])))
ax.view_init(elev = 10, azim = azi)
ax.dist = 10

plt.show()  

The set_axes_equal(ax) is taken from here.

How to keep the red point in the view and how to calculate an exact ax.dist value?