   Generating a Frustum
  Normally, when using OpenGL one can easily find the current viewing frustum by requesting the modelview and projection matrix, and then doing some arithmitic on them. My question is how to do this without OpenGL, I am writing a server app and it needs to know what to refresh for the clients and what not to, it uses a viewing frustum for each client to figure this out, but I do not know how to create this frustum. I have access to all of the camera infornmation about the client, such as FOV, perspective parameters, etc. Thanks, ~SPH 
  You need to manually create the matrices for the player i.e. projection and modelview, multiply them together and then extract the matrices from the resultant matrix. ;Yes but, I do not know how to do that (not a large math background).Thanks, ~SPH;  I'll assume you know how to multiply matrices. If not you can google for it - it's quite simple really.The projection matrix takes the form:  A 0 0 0  0 f 0 0  0 0 B C  0 0-1 0where f = cot(fov/2) a = f/aspect b = (far + near)/(near-far) c = ( 2 * far * near)/ (near - far)The modelview is done a little differently depending upon what info you store in your camera. This site explains it better than I could and is basically the way that gluLookAt works ClickyJames [edited by - jamessharpe on July 31, 2003 6:41:18 PM]