Re: [Assimp-discussions] aiProcess_GenNormals question

[David N. <co...@kl...>]

On 30 May 2017, at 11:49, David Rivkin, PhD wrote:
> Why does aiProcess_GenNormals (option to Importer::ReadFile())
> generating a list of Normals for each vertex when there should be just 
> 1
> per Face, and hence the array of mNormals should be equal to the
> aiMesh.mNumFaces, not aiMesh.mNumVertices?

Vertex normals are/were commonly used in realtime graphics. I'm sure 
you'll find more details on Wikipedia. You can express face normals 
using vertex normals by duplicating vertices that belong to more than 
one face as required. In fact, Assimp will already do this if you ask it 
to generate face normals during importing.

> I would consider this a bug.

It isn't. The conventions of real-time 3d graphics (which is where 
Assimp originated from) might just be different from whatever you expect 
from your field.

   — David