Vertex Normals

Hello all. I am currently trying to get the vertex normals to work so that my models can have each light value per pixel interpolated between vertices (i.e smooth shaded as opposed to flat shaded). I think I can calculate the normals using cross product vectors etc. I also understand that using glshademodel I pass either gl_flat or gl_smooth as the shade parameter.

What I am interested in is how do you tell OpenGL that you are handing it vertex Normals as opposed to Polygon normals? There is only one function glNormal (+ params) so I cannot see how this information is passed to opengl.

If I have explained myself badly or you don’t understand exactly because I am talking bollocks then please reply and I’ll try to clarify the above!!!

Thankyou in anticipation

AlCOrtholite

If you are specifying face normals you only need one normal for all vertices in the face:

glNormal();
glVertex();
glVertex();
glVertex();

otherwise one normal per vertex:

glNormal();
glVertex();
glNormal();
glVertex();
glNormal();
glVertex();

Cheers gumby

Ur a stallion!

State of the art graphics here I come…