# Help on changing the color of a poly edge in Makie

**URL:** <https://discourse.julialang.org/t/help-on-changing-the-color-of-a-poly-edge-in-makie/102999>\
**Category:** General Usage\
**Tags:** plotting, makie, 3d, polygons\
**Created:** [August 20, 2023, 9:18am UTC](https://discourse.julialang.org/t/help-on-changing-the-color-of-a-poly-edge-in-makie/102999 "2023-08-20T09:18:29Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![marteaua](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/marteaua/32/214927_2.png) [@marteaua](https://discourse.julialang.org/u/marteaua)\
**Post date:** [August 20, 2023, 9:18am UTC](https://discourse.julialang.org/t/help-on-changing-the-color-of-a-poly-edge-in-makie/102999/1 "2023-08-20T09:18:29Z")

</div>

Hi, I plotted a small 3D mesh using `poly` in Makie, I use a `LScene` because I want to put several 3D axis and do camera rotations.  
I try to change the color of one of the edge of the mesh. My idea is to plot the edge above the mesh, using poly, but it crashes when I try to plot the line in the LScene. MWE:

```julia
using CairoMakie

#### mesh data set up
vertices = [0.0 0.0 0.0; 0.7 0.2 0.1; 0.5 0.9 0.0; 0.5 0.35 0.9; 0.0 0.7 0.6;]
faces = [1 2 3; 1 2 4; 2 3 4; 1 2 5; 2 3 5; 3 1 5; 4 2 5; 4 3 5; 4 1 5;]
volumes = [1 2 3 5; 1 2 5 4; 2 3 5 4;]
vlist = [Point3(x) for x in eachrow(vertices)]

#### plot
fig = Figure(; resolution=(800,300))
lscene1 = LScene(fig[1, 1], show_axis=false)
poly!(lscene1, vertices, faces, strokewidth=3, shading=true, color=:transparent, strokecolor=:black)

points_of_edge_to_color = [vlist[2],vlist[4]]

# this works (but plots in a different, 2D axis)
# poly(points_of_edge_to_color, strokewidth=true, strokecolor=:red)

# this crashes, when the fig is displayed
poly!(lscene1, points_of_edge_to_color, strokewidth=true, strokecolor=:red)
fig

```

The error is

> Error showing value of type Figure:  
> ERROR: MethodError: no method matching iterate(::Nothing)

Thank you by advance for any help 🙂