Wave grooves on (ring) mesh For straight grooves, I use the Bevel tool, and some simple extruding and scaling operations. However, I also want to place an oblique line on a ring (so seperate the ring into two piece for a 2 coloured ring). Furthermore, not only straight but also wave-shaped grooves as follows. (from the wedding ring front view)

I want to ask for help on how to place an oblique line and wave-shaped grooves on ring.
Thank you in advance for your help!
You could use the Simple Deform/Bend modifier:

Create your curve, use bezier curve if you want, then convert to mesh, use LoopTools &gt; Space to make the space between vertices regular:



Extrude up and down:



Give it the Simple Deform modifier, choose the Bend mode, bend 360° on the Z axis:



Keep a copy somewhere, apply the modifier:



Extrude inwards, merge the vertices by distance, delete the inner faces if you have some:



Bevel the curve, extrude inwards:



Give it a Subidivison Surface, add some edge loops to sharp the edges, etc...