Line width in plot

[mmagnuski]

Is it possible to set line width when using ipyvolume.pylab.plot? The docs do not seem to mention this and I could not find any info on this anywhere else too. If it is not supported currently in plot - are there any hacky ways of achieving line width?

[maartenbreddels]

Hi Mikolaj,

It's basically not supported any more by WebGL (vs 1 at least):
https://developer.mozilla.org/en-US/docs/Web/API/WebGLRenderingContext/lineWidth
If it works (windows and/or linux may actually sometimes support it, I remember seeing it having effect on linux), you can try this out (using master from github).

import ipyvolume as ipv
import numpy as np


x = np.linspace(0, 10, 100)
y = np.sin(x)
z = np.cos(x)

ipv.figure()
p = ipv.plot(x, y, z)
p.material.linewidth = 2
ipv.show()

Let me know if you get success!

cheers,

Maarten

[vidartf]

@maartenbreddels three.js r91 added code in examples for fat lines via shaders, see mrdoob/three.js#11349. I'm considering exposing it in pythreejs given its usability.

[maartenbreddels]

Ah great, I saw some external libraries, but didn't know if I wanted to depend on that, if you plan to support it, I'll try to follow it.

[mmagnuski]

Thanks @maartenbreddels! I will test it. The page you linked seems to indicate that Edge browser has full support for lineWidth? That is unexpected, but I will test it out.
I may encounter problems installing ipyvolume from git on Windows (had some problems previously with npm etc. and didn't solve that) so it may take some time. :)

[maartenbreddels]

On windows, I recomment using anaconda, and then install nodejs:
$ conda install -c conda-forge nodejs
Good luck!

[5aurabhpathak]

As of writing this, the current hack to adjust the linewidth is the following:

import ipyvolume as ipv
import numpy as np

num_pts = 1000
x = np.linspace(0, 10, num_pts)
y = np.sin(x)
z = np.cos(x)

ipv.figure()
p = ipv.plot(x, y, z)
p.material.visible = True  # this is required for the following to work 
p.size = 1.  # adjust this number for linewidth. can also be more or less than 1.
ipv.show()

This will draw the scatter points along the length of the line. The thickness of those can be adjusted. If there are a sufficient number of such points, this will give the illusion of linewidth. It will not work as well if the number of points is too few. One can experiment with num_pts to see the effect.