i test unwrap on a small landscape with vertex painting and it's good
I think i've got to much error on my mesh or poly,it's my problem
...........................30 min after this post ,i re test on Lost_island map,cleaning UVW & materials,channels,etc...and now the textures is not strecthed,looking so good,i'm happy Thx for your help MERCIIIIIIIIIIIIIIIIIIIII!!