Danny Boyle wanted to make the movie that was the most energetic anyone had ever seen about something that ends up in purgatory or worse. Despite the obviously art house subject his intent was to make a film everyone would go to see.
Boyle's influences in making this movie were older classic films that featured rebellious youth, primarily The Hustler and A Clockwork Orange. He created the grungy look of the film by shooting the majority of the film's scenes in one take out of one location, an abandoned warehouse in Glasgow. When Renton sinks to the floor after overdosing on heroin Boyle commissioned the crew to build a platform above a trap door and lowered the actor down.Boyle was also greatly influenced by non-cinematic classics such as Thomas Pynchon's 1973 novel Gravity's Rainbow which inspired the scene where Renton dives in a toilet. Similarly Boyle used the colors of Francis Bacon paintings to influence the overall look of the film, creating a land between fantasy and reality.
Boyle wanted the film to be a British Pulp Fiction consequently using the soundtrack as another way to set the mood of each scene. The soundtrack went on to be one of the best-selling soundtrack albums of all time and a companion volume of music that had influenced the director whilst making the film was also released.
Throughout the movie Boyle's passion for portraying the least savory elements of society's underbelly without glamorizing it in any way is ultimately what makes it so gritty and hard hitting.