Assimp: one material per mesh

A mesh does use only a single material. If an imported model uses multiple materials, the import splits up the mesh. Use this value as index into the scene's material list.

Converting OGLDEV samples to SDL using GLM

When you convert OGLDEV samples to SDL using GLM, you might run into trouble. GLM is column-major and the OGLDEV samples are row-major.

This is not a big problem. Just invert the GL_TRUE in glUniformMatrix4fv to GL_FALSE. See this post: http://stackoverflow.com/questions/20578922/cant-display-model-using-glm-lookat-and-glm-perspective

DDS mipmaps creation

You want to create DDS mipmaps for using compressed textures in OpenGL? Just use Paint.NET 3.5+
No need to download "The Compressonator" for that.
The funny thing is that I tried to convert a JPG to DDS with "The Compressonator", but the JPG format was not supported. So I went to Paint.NET to convert the JPG to an other format. However when choosing the output type I discovered that Paint.NET can save DDS's and create mipmaps! Great free software that Paint.NET.

There also is available a bulk image processor: http://pdnbulkupdater.codeplex.com/