Hey guys !

I have a problem with my shader on my heightfield, it doesn't apply everywhere and i don't know how to figure it out..
I followed this tutorial by houdini : https://youtu.be/QdExA84aTLw?si=zy4Xa5mnPbXhW2KO [youtu.be]

Can anyone help me pleaaase ? :S

here are my render in viewport and in composite view