# How to plot coastlines on 3D earth

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Cielo Martos on 11 Feb 2021
Commented: Cielo Martos on 14 Feb 2021
I'm trying to plot coastlines on a 3D Earth I made
E=wgs84Ellipsoid
[x,y,z] = ellipsoid(0,0,0,E.SemimajorAxis,E.SemimajorAxis,E.SemiminorAxis);
s = surface(x,y,z);
[N,R] = egm96geoid;
s.FaceColor = 'texturemap';
s.CData = N;
So far this is what I have and i want to overlay coastlines from the mapping toolbox but, I don't know how to do that.

Ryan Klots on 12 Feb 2021
Currently, you are plotting (x, y, z) data as you would on a Cartesian axes. If you want to combine this with (lat, lon) data, you need to somehow convert between the two.
For example, you could use the geodetic2ecef function from Mapping Toolbox to convert from (lat, lon) coordinates to (x, y, z) coordinates:
% Convert from (lat, lon) coordinates to (x, y, z) coordinates
[X, Y, Z] = geodetic2ecef(E, coastlat, coastlon, 0); % E is your reference ellipsoid
% Plot (x, y, z) coastline data on top of existing sphere
hold on
plot3(X, Y, Z, "Color", "red", "LineWidth", 5);
hold off
Alternatively, you could consider sticking with (lat, lon) data exclusively and using something like geoglobe:
% Initialize geoglobe
f = uifigure();
g = geoglobe(f);
% Plot coastlines on geoglobe
geoplot3(g, coastlat, coastlon, 0, "Color", "red", "LineWidth", 5);
In either case, it's critical to pay attention to the coordinate system that you are working in.
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Cielo Martos on 14 Feb 2021
Nevermind I see the problem now!
plot3(-X, -Y, Z, "Color", "red", "LineWidth", 5);