Jan van den Hemel writes: If you’ve sketched a design on top of a curved surface using Grease Pencil, you can convert it to a Mesh outline in order to give you a headstart with retopology. It takes a few steps to set it up, which is explained in this video.
from BlenderNation https://www.blendernation.com/2021/08/20/grease-pencil-strokes-to-mesh/
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