noun
facet normal
Technical term in 3D computer graphics; a vector perpendicular to a polygon facet, used for lighting calculations.
3Dモデルの陰影計算には、各面の小面法線が必要です。
For shading calculations on a 3D model, the facet normal of each face is needed.
法線 is a general term for a normal line or vector, while 小面法線 specifically refers to the normal of a small polygonal facet in computer graphics.
Compound of 小面 (small face/facet) and 法線 (normal line), a direct translation of the English term 'facet normal'.