I am making an easy model, but trying to add multiple materials to it, and Blender is driving me mad. First I make the three materials, and then when I try to assign them the problem occurs. Every time I assign a material with the others I get some vertices (a faceloop) left inside one of the other material groups. Which is preatty ugly rendered. So I have 2 materials for some vertices, but not for faces.
Is there some way to remove vertices from a material group without deleting it and starting all over again.