In the world of real-time rendering, a lie well told is better than a clumsy truth. And no lie is more elegant, or more misunderstood, than the weighted normal.
In the end, weighted normals teach us a profound lesson about computer graphics: And a well-weighted lie is indistinguishable from the truth. weighted normals
Enter .
To fake smoothness, we use vertex normals —averaging the normals of all the polygons that meet at a single corner. This is the classic "smooth shade" button. It works wonderfully for a sphere. But for a cylinder? You get a strange, pinched artifact at the top and bottom. For a game character’s hard-edged armor? The edges look like melted plastic. In the world of real-time rendering, a lie