Take the tour ×  I'm loading the exact same model with Assimp,
except one is exported from Blender, shaded smoothly, and the
other was exported from Blender, shaded flatly. Here is my
results from loading both into my game: enter image description
here  The Flat drawn model has 1968 vertices and the Smooth
drawn model only has 671, why is this happening, I don't
understand why there would be less vertices when it's shaded
smoothly...?  share|improve this question They are the exact
same models, I'm calling mNumVerctices for both of the scenes
that they are apart of and getting the numbers –  Brendan
Webster May 19 at 3:21 add comment  1 Answer  up vote 3 down
vote accepted  For smooth shading, two adjacent triangles must
share common vertex normals. The reason is interpolation. The
normal from one vertex is smoothly interpolated to the normal on
the second vertex. You need to ensure that the normal of
triangle at a particular vertex matches the normal of all
adjacent triangles at that same vertex. If you thin