Matplotlib 3D plot - parametric curve "bypass" from certain points of view

Question

I am writing a Python script ( GitHub LINK ) to render asteroids / comets / meteoroid orbits. The script also displays the position of the planets and their orbits.

It works correctly for orbits with a small semi-small axis (ie, "smaller" orbits). But when I have an orbit that goes beyond Neptune (for example, Halley's comet), and from some points of view there is a strange effect of "deception" (due to the lack of a better word).

Let me show you what I mean:

Image compilation: http://i.imgur.com/onSZG8s.png

• This image shows the graph in terms of where it will not break.

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from mpl_toolkits.mplot3d import Axes3D
import numpy as np
import matplotlib.pyplot as plt

def orbitalElements2Cartesian(a, e, I, peri, node, E):
    """ Convert orbital elements to Cartesian coordinates in the Solar System.

    Args: 
        a (float): semi-major axis (AU)
        e (float): eccentricity
        I (float): inclination (degrees)
        peri (float): longitude of perihelion (degrees)
        node (float): longitude of ascending node (degrees)
        E (float): eccentric anomaly (radians)

    """

    # The source of equations used:
    # http://farside.ph.utexas.edu/teaching/celestial/Celestialhtml/node34.html

    # Check if the orbit is parabolic or hyperbolic
    if e >=1:
        e = 0.99999999

    # Convert degrees to radians
    I, peri, node = map(np.radians, [I, peri, node])

    # True anomaly
    theta = 2*np.arctan(np.sqrt((1.0 + e)/(1.0 - e))*np.tan(E/2.0))

    # Distance from the Sun to the poin on orbit
    r = a*(1.0 - e*np.cos(E))

    # Cartesian coordinates
    x = r*(np.cos(node)*np.cos(peri + theta) - np.sin(node)*np.sin(peri + theta)*np.cos(I))
    y = r*(np.sin(node)*np.cos(peri + theta) + np.cos(node)*np.sin(peri + theta)*np.cos(I))
    z = r*np.sin(peri + theta)*np.sin(I)

    return x, y, z


if __name__ == '__main__':

    # Example orbital elements
    # a, e, incl, peri, node
    orb_elements = np.array([
        [2.363, 0.515, 4.0, 205.0, 346.1],
        [0.989, 0.089, 3.1, 55.6, 21.2],
        [0.898, 0.460, 1.3, 77.1, 331.2],
        [104.585332285, 0.994914, 89.3950, 130.8767, 282.4633]
        ])

    # Setup the plot
    fig = plt.figure()
    ax = fig.gca(projection='3d')


    # Eccentric anomaly (full range)
    E = np.linspace(-np.pi, np.pi, 100)

    # Plot the given orbits
    for i, orbit in enumerate(orb_elements):
        a, e, I, peri, node = orbit

        # Take extra steps in E if the orbit is very large
        if a > 50:
            E = np.linspace(-np.pi, np.pi, (a/20.0)*100)

        # Get the orbit in the cartesian space
        x, y, z = orbitalElements2Cartesian(a, e, I, peri, node, E)

        # Plot orbits
        ax.plot(x, y, z, c='#32CD32')

    # Add limits (in AU)
    ax.set_xlim3d(-5,5)
    ax.set_ylim3d(-5,5)
    ax.set_zlim3d(-5,5)

    plt.tight_layout()
    plt.show()

. !

Answer 1

matplotlib 3D- ( ). - , 3D-...

, np.NaN . :

for r in [x,y,z]:
    for i in np.arange(len(r)):
        if r[i] < -5:
            x[i] = np.NaN
            y[i] = np.NaN
            z[i] = np.NaN
        elif r[i] > 5:
            x[i] = np.NaN
            y[i] = np.NaN
            z[i] = np.NaN
        else:
            pass

.

Answer 2

- . javascript webGL- Three.js, , , / . -. :)

http://rankinstudio.com/asteroids/asteroids.html