Bumping armchair surface

Hi everyone,
I am Valentin a french designer. I hope you guys could help me for this topic.
I am working on a new armchair design. I would like to have a bump effect like a cushion on the sit (see for example the pic enclosed). What are the different steps to realize it ? For the moment I only have my blended surfaces.
Thanks in advance

Valentin

Hi Valentin, @v.codemard
You might use Displacement - Render mesh modifier "…The displacement map differs from a bump map set by the rendering material in that the displacement mesh is a real object with edges that produce real highlights and shadows.
https://docs.mcneel.com/rhino/6/help/en-us/index.htm#properties/displacement.htm

Hi @Fred_C,
First of all thanks for your reply.
I think that I wasn’t clear on my request, sorry for that.
I do not want to have a render bump on my armchair but i would like to know, how may I draw a surface which seems like a cushion ?

Brian James made wrinkled stereo headphones by moving control points: