Creating a Shell/Scroll/Fossil with a Pattern in Rhino

Untitled.3dm (3.4 MB) Hello,

I want to create a shell with an entrace. The outside should be edgy and have gaps that bent inwards. Sort of like this: fossil fossilized ammonite jurassic england english Garantiana Stock Photo - Alamy but more “edgy”.

I followed along some tutorials on youtube but they all included a round shell, if i make it an edge it looks weird. Modeling a scroll with Rhino 5 (Beta version) - YouTube

Should i maybe approach this with layers or how would I go about to make the gaps from top to bottom? And how would I go about to try and make this a solid with walls?

I’ve attached my attempt after trying out for some hours.
Thanks in advance
Lisa

I’d suggest using the Spiral command first with the flat option. Then Pipe on that curve using different radii at the ends making it overlap itself. You can then use Drape and Trim that surface to get your base shape. The detail ridges would best be done using the Displacement property in the Properties panel. I used a Planar mapping method for the surface and a blurred screenshot of your reference image for the displacement but you could use anything.

Did you see this discussion?

My logo is done using if.