switch to turn off auto-shading in scatter3D

[tspr]

from the mailing_list:

Hi folks!
maybe you can point me in the right direction:

I have a list of colour measurements in Lab-Space(stored in an h5 table). Now, 3d-scatterplotting them was easy, also, assigning the corresponding rgb colour value to the spots is relatively easy.

For the plot i use:

p=ax.scatter3D(table.cols.Lab_a[:],table.cols.Lab_b[:],table.cols.Lab_L[:],c=cols)

Now, the annoying part: when i move around the figure with the mouse, the points in the background get "dimmed" or shaded to have less saturation. Now in my case, i want to turn this behaviour off, since i want the points to be the colour they represent, all the time.

How do i do this?

thanks for your help

Thomas

Unfortunately, there is no setting to turn this feature off. However, I don't see why it couldn't be done. It would be great if you could file a feature request on our github page.

Cheers!
Ben Root

[dhyams]

Thomas:

If you are willing to hack your mpl source a little, this can be disabled by commenting out the following lines that I have marked below with REMOVE_ME, in mpl_toolkits/mplot3d/art3d.py.

def zalpha(colors, zs):
    """Modify the alphas of the color list according to depth"""
    # FIXME: This only works well if the points for *zs* are well-spaced
    #        in all three dimensions. Otherwise, at certain orientations,
    #        the min and max zs are very close together.
    #        Should really normalize against the viewing depth.
    colors = get_colors(colors, len(zs))
    if zs.size > 0 : # REMOVE_ME
        norm = Normalize(min(zs), max(zs))  # REMOVE_ME
        sats = 1 - norm(zs) * 0.7  # REMOVE_ME
        colors = [(c[0], c[1], c[2], c[3] * s) for c, s in zip(colors, sats)]  # REMOVE_ME
    return colors

It just depends on how desperate you are ;)

[michiexile]

Bump! I need this feature too, for pretty much the same reason as Thomas.

[jclevesque]

To me this seems like a feature that should be considered. I'm trying to overlay information on a surface plot and this colouring thing is making my life much harder.

[tspr]

Am 21.03.2014 um 14:40 schrieb Julien-Charles Lévesque:

To me this seems like a feature that should be considered. I'm trying to overlay information on a surface plot and this colouring thing is making my life much harder.

It's been a while; and ever since, i switched to Anaconda. Re-learned the stuff and found some tricks.

Now, in order to get rid of the annoyance, there is no more need to patch:

...

Start plotting

Disable depth shading

plt.ion()
art3d.zalpha = lambda *args:args[0]

Setup canvas

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

plot the points

pointsplot=ax.scatter3D(avals,bvals,Lvals,s=20,c=colours,linewidth=0)

...

hope, this works for you as well!

Thomas

—
Reply to this email directly or view it on GitHub.

[dopplershift]

This is the same problem you saw, @jrleeman.

[WeatherGod]

so, looks like in py3.3, the reduce() builtin is gone. It is fishy why this hasn't failed before (and why 3.4 doesn't fail either). We can easily use six, though.

[WeatherGod]

Ok, and it looks like I commented in the wrong place...