Faking a view plane camera

[Edward K. C. <ek...@ma...>]

Not sure if this would be of use to anyone, but I came across a  
function I wrote awhile back to get a view angle aspect camera to  
behave more like a view plane camera.  I guess I wrote it because at  
the time, Quesa hadn't implemented the latter.  If view plane cameras  
are now supported, well then, never mind...

It's sort of a half-implementation, in that it only converts from  
TQ3ViewPlaneCameraData to TQ3ViewAngleAspectCameraData and not the  
other way around, but that's all I needed in my case.  Also, I had to  
strip out some C++ class code to generalize it better, so hopefully  
that didn't break anything.

-Ted