Robin Williams' limitless improvisation on the set of "Mrs. Doubtfire" resulted in an overwhelming amount of material

It's been 30 years since "Mrs. Doubtfire", featuring Robin Williams, first premiered. Williams was a wellspring of ideas, resulting in so much filmed material that there could be several alternative versions of the movie. Director Chris Columbus has retained many unused scenes, from which he plans to create something exciting.

"Mrs. Doubfire" tells the tale of an unemployed and irresponsible actor, who, in an attempt to maintain contact with his children post-divorce, gets employed as an elderly housekeeper in his ex-wife's home. The film, which had a budget of 25 million dollars, grossed over 400 million worldwide. The standout aspect of the film was, without a doubt, Williams' performance in the eponymous role.

Williams, an already established star, informed the director from the onset about the spontaneous nature of their on-set work. The actual script was merely a rough guide. The crux of the interpretation was the improvised versions of each scene by Williams, something that occasionally led to technical issues.

"I got to the point where I had to utilize four cameras continuously in order to keep pace with him. None of us knew what he would say once the clapperboard struck, so I wanted to film the other actors to capture their spontaneous reactions," recalls Chris Columbus in an interview with Business Insider.

Filming was non-stop until Williams decided it was sufficient. As the director reported, they used approximately 404 miles of film reel in total.

"If Robin was filmed with digital cameras, he would have never stopped," Columbus joked.

The unused footage still resides in storage.

"There are roughly 972 boxes... We plan to hire an editor to sift through this enormous collection. There is something truly remarkable and magical in Robin's approach to his work. I believe it would be worthwhile to delve into and showcase this creative process," stated the director.