Interesting carpets: https://3dsky.org/user/favorites/models_collection/5439437 
Lint-free wool carpet
The volume is made by Normal and Displacement maps.
Don't forget to enable and configure Displacement display in the settings.:
Common -> Options -> Displacement. To detail the volume, go to the Perfomance -> Displacement -> Screen size(px)=2
! Uncheck 2.5D displacement!

https://www.westelm.com/products/colca-wool-rug-t1657/