   Model Normal -  FVB
  I just start working with DirectX, and I'm trying to understand how to load normal vectors from Milkshape3D into a flexible vertex structure. For most model formats, normals vectors are not mapped to vertices, but are referenced from each triangle list.For example consider the following triangle definition line from Milkshape:flag Vind1 Vind2 Vind3 Nind1 Nind2 Nind3 SGroupMy first thought was to map Normal(Nind1) - > Vertex(Vind1) in the Flexible Vertex structure. This seems kinda redundant because vertices can be defined in more then one triangle. Is this correct? I'm curious if there is a beter technique..   
  I've not dealt with milkshape files directly, but I have seen a few file formats similar to what you describe.Typically the answer is to use "smoothing groups" to combine the normals. If you're using indexed meshes it is usually quite easy to get a list of all the different normal for a shared vertex then add them together and re-normalize.Where it gets tricky is around mesh boundaries or 'hard' edges - some artists will specifically detach edges like this to ensure that the lighting reflects the shape correctly (for example, a right-angle edge can appear smooth/rounded if the normals are averaged across it). Detecting where these hard edges is can be a bit tricky depending on the file format - for indexed meshes or formats where some sort of material group (e.g. for textures) is used you're ok, but if you literally only have the vertex data and no material data you may be out of luck.hthJack   