   Orthographic camera primer?
  I'm experimenting with using an orthographic camera projection for my skydome....never played with ortho projection before...doesn't display the skydome, just a big white circle.  Previously I was using a perspective camera...projectionMatrix = CreatePerspectiveFieldOfView(MathHelper.ToRadians(45), aspectratio, nearclip, farclip);And this is the ortho camera projection matrix that doesn't work...orthoProjectionMatrix = CreateOrthographic(Viewport.Width, Viewport.Height, nearclip, farclip);I basically want the same view as from the perspective cam, but with an ortho cam.  Any idea what I'm doing wrong?THANKS   