How to set a color or label on an shape face?

[njourdane]

For debugging purpose I would like to add a color and label to a shape face.

Something like that:

box = Box(4, 2, 1)
box.edges()[0].color = 'green'
box.edges()[0].label = 'back'

show_object(box) # show the box with one green face.

And same for edge, vertex, etc. Is it possible ?

edit: I managed to do this by directly displaying the faces:

box = Box(4, 2, 1)
faces = list(box.faces())
faces[0].color = 'green'
faces[0].label = 'back'
show_object(faces) 

But Maybe there is a better approach?

[jdegenstein]

As you might have surmised, build123d does not support having more than one color per object. I also regularly need functionality to "highlight" specific faces/edges/vertices but I approach it in a far less manual way using some of the features of OCP CAD Viewer. I have found that if the manual approach is too tedious then I simply avoid using it which negatively impacts my overall modeling productivity.

from build123d import *
from ocp_vscode import *
set_port(3939)
show_clear()
set_defaults(ortho=True, default_edgecolor="#121212")

with BuildPart() as p:
    Box(1,2,.5)
    Box(.5,1,.5,mode=Mode.SUBTRACT)
    someface = faces().sort_by(Axis.X)[-1]

set_colormap(ColorMap.seeded(colormap="rgb", alpha=1, seed_value="vscod"))
show_all(reset_camera=Camera.KEEP)

The first key line is set_colormap which has many possible configurations, but I personally use a seeded random color distribution at the expense of control but in my opinion the huge benefit of it not being a tedious process. I also recommend using show_all which again helps reduce the tedium of the visualization side to focus on the much more important modeling side.

I personally use a VSCode snippet which provides a file template for build123d modeling as well as some shortcuts. My snippet is available here https://gist.github.com/jdegenstein/6233ac42632d9098c99da029fe0615c2