I am using assimp as a tool to import different 3d models and convert them to my own format which is then loaded by the game. I am at the point where I want to implement lightning, and one of the things I need is the normals for a mesh.
I have a basic cube made in blender, which when exported does not come with any normals defined.
I read about the assimp flag 'aiProcess_GenNormals' (http://assimp.sourceforge.net/lib_html/postprocess_8h.html#a64795260b95f5a4b3f3dc1be4f52e410) which sounded great, but I noticed that when I use it for some reason the number of vertices 'mNumVertices' in the mesh grows from 8 to 24, and later when I try to render it something broke in OpenGL as nothing is rendered.
Why would assimp possibly report triple the number of vertices in the scene when generating normals?