Creating A simple Pyramid

Hi I am really bad with math in 3d (2d i am not bad but 3d… sheesh) so bear with me. I am trying to create shafts of light so i am making a 3d pyramid that i will apply cute little trasnparent light textures to it. No i want to specify the pyramid with three values Start vertex, End vertex, and apeture. here is an ascii pict.

  • is first
    & is end


and the apeture is the * to hypotenues. I just need somewhere to get started and some guidance on how to achieve this.


the shape u want sound like a perspective view frustum (without the near clipplane) eg gluPerspective(FOV,aspect,near,far)
theres quite a few examples of how this works