flat/gourad shading question
For a project I have a terrain (height map), for which I preferably would only like to use 1 vertex per height point, but the problem is that I would like to have hard edges. If I use flat shading it looks good without any lights, but if I add lights it will light up the terrain on triangle basis, instead of per vertex, and this doesn't look good. If I use gourad shading however, I can't seem to get around making 3 vertices for each triangle, so that I can point the normals for each triangle outwards so I can the hard edges. But it seems a waste of vertices. Is there another way that i can achieve a lighting similar to gourad, have hard edges, and only use 1 vertex per height-point in my map?
Thanks a lot for any information!!