Finding "normal" direction at intersection of a polyhedron

[laurent_delrieu]

Ponderate mean that instead of doing the sum of normals and then unitize this sum you multiply each face normal by face area then sum and then unitize.
It is a weighted mean.

First journey in 3D printing

Some weeks ago I began my journey in the 3d printing world. The main job was to generate 3d printer paths from closed curves which represent the intersection between a slice (plane or not) and a solid. The paths must be a single curve, which means the extruder never stop to extrude during the print. The results are very similar from what is presented here and on this paper “Connected Fermat Spirals for Layered Fabrication” The main tool is Offset from Clipper but there are many optimizatio…