IIRC, there were companies running pure CGI simulators in the 70's, so that could be the out of the window imagery for the astronauts. I'd love to know more about the software (and, mostly, what appeared on the three MFDs of the original shuttles, as well as detailed images of the glass-cockpit MFDs that are on this simulator.

IIRC, the original ones were not raster displays, but long-persistence X-Y displays.