In 3D modeling, a line set defines which edges are rendered as strokes in a non-photorealistic style

https://andrespnrp320.opalvector.com/posts/mini-split-line-set-accessories-that-make-installation-easier

In 3D modeling, a line set defines which edges are rendered as strokes in a non-photorealistic style, controlling visibility, crease emphasis, silhouette extraction, and intersection highlights for stylized visuals.