Who You Gonna Call?
The Ghostbuster show set up was almost identical to the way the Twister attraction is set up. There were not many major physical changes to the contruction of the show building itself.
In Twister, the audience stands in long horizontal rows facing the show area. In GB, those rows had seats, but the basic orientation was the same. The seating was similar to the second theater in the Hitchcock (The Art of Making Movies) show (RIP). Only 7 or so rows deep, but pretty wide.
In Twister, the audience has a roof above them. Same in GB. Right now, there is a large open area above the audience, like a giant balcony, that has a number of air movers (large industrial-type fans) and semi-circle curved walls that create the "twister" of air. In GB, that balcony was also there, but it housed a number of animatronics and lighting effects that reflected off the glass between the audience and the show/stage area. The effects were not "projected," but were simply "reflected." It's called the Pepper's Ghost effect. It's like looking out a window at night time. You see a reflection of yourself, or a "ghost." When effect lights turned on the particular animatronic ghost, like Slimer, he would "appear" in the show area (his reflection on the glass wall.)
The backdrop of Twister illustrates a natural open sky. In GB, there was a mock Temple in the show area (from the top of the building from the frist GB movie) whose backdrop was also open sky. They just had to repaint it from blue (daytime in GB) to blackish colors (nightime in Twister.)
It's really amazing how little they had to do to the GB building to create a completely new attraction.
The "lasers" shot from the GB guns were created by flickering "tube lights" placed on the balcony above the audience. Because the stage was well elevated, the audience must look up, and they see the reflection of the tangled lights to appear in the stage area. If the actors didn't hit their mark, or if you had a seat near the ends of the row, the lasers woudn't exactly match up with the guns or the ghost characters. The light pattern was pretty sparatic, though, the mis-alignment was commonly noticeable.
You gotta give the creators props for creativity, though. They took an effect used in the Haunted Mansion (and decades before that) and turned it into an entire interactive show.
Tk