Low Poly terrains issue

[Firelods]

Hi everyone, I’m doing my first steps in Babylon, be indulgent
I am doing the start of a project where I am generating terrains.
I generate a height map from this website : https://heightmap.skydark.pl/
and then I want this terrain to be as the “render wireframe over mesh” to make the terrain like a low poly texture.
Here is my code : https://playground.babylonjs.com/#N16TE3#3
I saw some tutorials saying that I need to use terrain.convertToUnIndexedMesh() but when I put this line the program doesn’t launch.
Is there any other ways to do what I want ? Am I doing something wrong ?
Thanks by advance
style of what I want to do :

What i have :

[Evgeni_Popov]

Welcome aboard!

Your PG does not work in the Playground because the assets can’t be found:

Here’s a doc page that can help you storing assets for use in the Playground:

Using External Assets In the Playground | Babylon.js Documentation

[Firelods]

Hey, thanks for your advices, I uploaded my assets on imgur but the error persists and the console say me to notify you

The new link : https://playground.babylonjs.com/#N16TE3#9
Thanks by advance

[sebavan]

you need to convert when the mesh is ready not before: https://playground.babylonjs.com/#N16TE3#11

[slin]

You may need this to achieve the lowpoly terrain in your screenshot: Delaunay triangulation - Wikipedia