   Orthogonal Skydome, or what?
  I have a skydome.  I want the camera to be able to move up and down on the y axis without the skydome and it's features such as clouds becoming bigger.  I can't simply move the skydome relative to the camera along the y axis because the lower edge of the skydome will be higher than the actual landscape and the camera can see the vacant space between them.  And I can't put the skydome low enough below the horizon to compensate for this or the clouds will reflect all wrong on the water.  I'm not sure if rendering the skydome with an orthogonal camera is a good solution to this problem....experiments have yielded some wierd results.  1. Would anybody have any suggestions as to how to properly set up an orthogonal viewpoint for this purpose?2. Would anybody have any suggestions as to a better method for accomplishing this?THANKS   
  you know what I myself would do?  Render a scren-space quad with depth buffer writes turned off (s.t. the quad renders everywhere that is "background")In the shader for that quad, compute the vector between the camera's position and the fragment position, to get a vector pointing in the direction the pixel is looking.Interpret that as an environment map lookup for your skydome texture.Done.  No camera issues.   ;  There is a thread about the same issue on the very same page (DirectX and XNA)   