DriftEngineModel loading · function
faceNormals
Each face's normal, by the rule Blender uses for its size: two edges of a triangle, the two diagonals of a quad, and Newell's method beyond that.
Explained in Importing models.
function faceNormals(mesh: BlendMeshData): Float64Arrayimport { faceNormals } from '@driftengine/assets';Parameters
| Parameter | Type | Description |
|---|---|---|
mesh | BlendMeshData |
In depth
Not Newell's method throughout, which is what this was until a real file disagreed: a quad with two coincident corners has no area, so Newell gives it no normal, while its diagonals still cross. And where even they cancel — a quad whose corners coincide in pairs — Blender calls the face's normal straight up rather than zero, and averages that into its smooth neighbours. Both were found on a 2.79 wheel, where one such face moved a vertex normal 0.68 from Blender's.