Magica Voxel :)

https://github.com/Zarbuz/FileToVox By Zarbuz : you can transform a PNG image (s) in format .vox used by Magica

Here you can have any Height Maps of the entiere World ! Free https://terrain.party/

so this little of code
C:\Users\Pilou\Downloads\FileToVox-v1.5-win-x64\FileToVox.exe --i tapis.png --o tapis --hm 100 --c my_color.png

Makes the trick! :) (in this order)

--i tapis.png = Input any Height Map's Name here with some clouds :)

--o tapis = Output Any file.vox 'x name

--hm 100 = Height Map (too much take 20 for a reasonable one)

--c my= any 256 Colors image color.png

so somewhere in the world! :)