i resembled a cylindrical surface as mesh, and tried to optimize it - but nothing good came out.
2.3dm (961.6 KB)
The reference geometry is a cylinder, i exploded, deleted the top and bottom, and _rebuilt in rhino.
Then i placed a mesh box around it, deleted top and bottom, joined and _etwelded, subdivided, and optimized.
There is a seam in it, which causes a singularity as well. How can i solve that? What did i wrong?