I'm doing lighting in world space (not in eye space), so I set the normal matrix as follows:
modelProgram->setUniform( "NormalMatrix", inverse(transpose(mat3(modelMatrix))) );
Now I noticed that all the tutorials set the normal matrix as the inverse transpose of the ModelView matrix. This also means they do lighting in eye space, right?
Do I have to do lighting in eye space when using the normal matrix? I actually do normal mapping too if it matters.