I think you have to create separate vertices. But I think it's also the case that the blitz's updatenormals function will still smooth them so you will have to create your own normals, or more likely write your own routine to generate normals which does not do this, which should not be that hard, though it's not quite so trivial that I have got around to doing it yet.:) Actually I thought SSwift came up with something of the sort, but I can't see it in the code archives, so maybe I am imagining it.
Oh and I am pretty sure blitz does not do phong as that implies calculating the lighting at every pixel across the triangle which means generating a new normal for every pixel based on the averaged triangle normals which is too slow. Blitz does do Dot3 blending though which is similar in principle and as the normals are pregenerated it's a lot quicker. I believe true phong can now be done in hardware by using pixel shaders but thats post DX7 which is blitz's current high watermark so as to achieve maximum compatibility across a wide range of hardware.
Oh and I am pretty sure blitz does not do phong as that implies calculating the lighting at every pixel across the triangle which means generating a new normal for every pixel based on the averaged triangle normals which is too slow. Blitz does do Dot3 blending though which is similar in principle and as the normals are pregenerated it's a lot quicker. I believe true phong can now be done in hardware by using pixel shaders but thats post DX7 which is blitz's current high watermark so as to achieve maximum compatibility across a wide range of hardware.