TL;DR of the post, generated automatically.

OP's low-segment hair strands look wavy and bumpy, and they want to know how to straighten them.

• The problem: Hair strands built with a low segment count show wavy shapes with some bumps.
• The question: OP asks whether there is a way to straighten those hairs.
• The evidence: Three screenshots are attached, and the last one shows the hair settings OP used.