Normals Tips

Interactive figures to see how normals work in 3D graphics.

Contents

1. 1. What is a normal? — How the facing of a surface and the light angle decide brightness.
2. 2. Face normals and vertex normals — Flat vs. smooth, and splitting by angle.
3. 3. How to average vertex normals — Uniform, area-weighted and angle-weighted.
4. 4. Hard edges and UV seams — Split vertices do not break the shading. Split normals do.
5. 5. Custom normals — Change only the shading, keep the shape.
6. 6. Seams between separate meshes — Why the shading breaks, and common ways to match normals.
7. 7. Why toon shading shows normal errors — The threshold, and how much the surface curves.
8. 8. Normal maps — A normal map is built on top of the vertex normals.
9. 9. Things to watch on export and import — Normals can be rebuilt along the way.