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01HNNWZ0MV43FFtoday at 1:16 AM2 repliesview on HN

For the curious readers, backface culling (at least in the way fixed-function OpenGL does it, and probably newer APIs still do) is not based on face normals, it's based on winding order of triangles, so it works even if normals are not used.

Also face normals (flat shading) are generally considered older tech than per-vertex lighting (Gouraud shading). Newer stuff since 2008-ish is generally per-pixel using normal maps for detail.


Replies

Tanoctoday at 7:31 AM

If I remember my graphics accelerator history correctly per-vertex lighting using Gouraud shading was the method SGI made standard with OpenGL in 1992, before 3DFX and ATI came in and made per-pixel via Blinn-Phong just as computationally efficient in about 2000 or 2001. Used before Gouraud and then alongside per-vertex and per-pixel was per-face flat shading, which kept being used up until the Xbox 360/PlayStation 3/DirectX 10 era. Face normals for per-pixel started being used in 1999 by SEGA, but stopped being common around the same time as normals flat shading got abandoned.

If I'm wrong please feel free to correct any of this, it's been about eight years since I last learned all of the different methods.

nickandbrotoday at 3:20 AM

Thanks for clarifying, so I guess I already have it on then.