Matplotlib Line3dcollection For Time-varying Colors

I'm attempting to plot 3D line trajectories that evolve over time, and I would like the colors to change to show that passage of time (e.g. from light blue to dark blue). However,

Solution 1:

Your code works just fine, here's a bit of a sample. Basically, this is your code with a custom X set.

fig = plot.figure();
ax = fig.gca(projection = '3d')
X = [(0,0,0,1,0),(0,0,1,0,0),(0,1,0,0,0)]
points = np.array([X[0], X[1], X[2]]).T.reshape(-1, 1, 3)
r = [(1.0, 1.0, 1.0, 1.0), (1.0, 0.75, 0.75, 1.0), (1.0, 0.5, 0.5, 1.0), (1.0, 0.25, 0.25, 1.0), (1.0, 0.0, 0.0, 1.0)];

segs = np.concatenate([points[:-1], points[1:]], axis = 1)
ax.add_collection(Line3DCollection(segs,colors=list(r)))

plot.show()

And the plot looks like this:

Solution 2:

Wow, so it turns out the problem was that X was actually not of shape (3, n), but rather something like (3, n^10), but I was only plotting n points, hence the color appeared to never change (and why r seems to have extremely small intervals...there were something like 58,000 points when I was plotting only 250).

So yes, it was a bug. Sorry about that; it works fine now.