Assign colors to arrows in network graphs

Hi @marcomusy

This is a follow up to my previous post here https://github.com/marcomusy/vedo/issues/182#issuecomment-667694798

I could color the edges based on edge weights

edg.cellColors(vals, cmap='viridis', vmin=vmin, vmax=vmax)  #Blues_r
        edg.addScalarBar3D(
            title=' title',
            titleFont='VictorMono',
            labelFont='VictorMono',
            c='k',
            # titleXOffset=-1.5,
            # titleYOffset=0
        )
        
arrsv=[]
for i, j in G.edges():
    dv = nodes[j]-nodes[i]
    cn = (nodes[j]+nodes[i]) /2
    v = dv/mag(dv)*1.5
    ar = Arrow(cn-v, cn+v, s=.02, c='k')
    arrsv.append(ar)

show(pts, graph, labs1, labs2, arrsv)

This assigns colors to the edges and the arrows are colored black. Instead, I’d like to assign colors to arrows (something like arrsv.cellColors inplace of edg.cellColors/ cmap) instead of edges and also generate scalarbar for the colors assigned to the arrows (e.g. arrsv.addScalarBar3D() ).

Could you please offer suggestions on how to do this?

[marcomusy]

E.g.

from vedo import *
lut = buildLUT([
          (10, 'dg',),
          (40, 'red'),
      ],
          vmin=10, vmax=40,
          interpolate=False,
          aboveColor='yellow',
      )

rgb = [0,0,0]
lut.GetColor(58, rgb)
print(getColorName(rgb))

yellow

[marcomusy]

Just specify the color right after the cmap:

# manually build a lookup table for mapping colors
settings.defaultFont = 'VictorMono'  # set this as default if you like it, so it'll be used for axes too
edg.cmap('viridis', weights, on='cells').c('grey')