MANKATO — “Noises Off,” Allen Wright Shannon’s beautiful swan song in the Minnesota State University Theatre & Dance department, has proven to be quite demanding on the accomplished scene designer.

You might say, it’s caused a split personality to emerge. On one side, there’s the lovely Allen — a meticulous visionary who has brought such lavish, yet functional sets to the Ted Paul Theatre as “Peter Pan,” one of his favorites, “Hamlet” and “Cats.”

On the other side, there’s Atrocia, whose job it is to “not be very good.” She’s female, Allen said, “and she’s bitter.”

The need for Atrocia emerged due to the very essence of “Noises Off” — a multi-layered farce that is, essentially, “a play about a play within a play,” Allen said.

“Noises Off,” which opens tonight, is about a troupe of actors in a terrible sex comedy called “Nothing On.” And as that play falls apart during final dress rehearsal, when seemingly no one is prepared, to the end of its 10-week run, when no one gets along and everyone is bored, the hilarity ensues.

To illustrate the “play within a play” concept, Shannon brought out a revolving stage, which was used for a previous production. His team built a set on 16 pie-wedge-shaped pieces welded together for a frame, which was placed on a pivot and covered with plywood decking. The whole thing revolves to show a front and back side.

The front side is the set of “Nothing On.” So Allen had to design a set that looked like a set of a two-story home. (Still following?) This is where Atrocia came in.

“The people in the play are not very good, doing a play that is not very good,” he said. “I tried to design (the set) like I wasn’t very good.”

Instead of looking like actual doors, which is the goal of most sets of plays, the doors look like they were painted to look like doors with obvious brush strokes and detailing. Also, some of them don’t close properly.

On the second floor, the dormer — a structural element from a sloping roof surface — is purposely cut incorrectly. The slope is so acute that the room behind the door would be like a tiny closet with a plunging ceiling. And part of the dormer covers door moldings, which would be impossible unless the ceiling was built after the doors were installed.

“Architecturally, it doesn’t make sense,” he said.

The back side of the set is where Atrocia completely took over. The set revolves to show the audience the backstage action of the cast of “Nothing On.”

Allen had to make this side look like the actual backstage of a set, which means everything looks unfinished. It’s bare-bones wood with cables and wires sticking out and plastic chairs for the actors to sit on when they’re not in a scene. It’s hideous — but it’s right on the money.

One would imagine it would be easier to make a set purposely look “not that good,” as Allen often referred to it, and especially easy to leave the backstage unfinished. But there’s a lot to think about.

“This is the biggest small set I’ve done,” Allen said.

A designer like Allen is used to thinking in the opposite manner — to make a set look realistic and true to life and functional. It took Atrocia to completely reverse his thinking, especially when a little curve ball was thrown at them both.

He thought the revolving base was 32 feet across. In fact, it was 28.

“Atrocia had a little problem with it when I explained we had to go in 4 feet,” Allen said.

Allen will receive his master of fine arts degree in May and will leave the department, off to a whole new adventure in another job somewhere, assuming he gets one, he said. (“Say a prayer for me,” he joked.) For his final scene design at MSU, director Heather Hamilton said he did just what she had envisioned.

“I don’t think Allen is capable of touching a design without making it good,” she said. “The ‘design within a design,’ while perhaps a departure from his other work, in that he intentionally chose ugly elements such as hideous color schemes, is still a work of brilliance.”

Allen’s had a great time making a set that the audience is actually supposed to notice, almost like another character in the play. Usually, his job is to create an environment that plays a supportive role for the actors.

“If an audience comes to see ‘Hamlet’ and they leave not remembering the set, I’ve done my job,” Allen said. “I think that’s what good design is. ... In this one, it’s OK for the audience to remember the set.”

Heather says they will. And she, and everyone else in the department, will remember Allen — and Atrocia, too.

“Allen will be very sorely missed,” Hamilton said. “He’s an absolute gem.”