Karthik said he had first run the idea past Rajinikanth four years ago, but things did not materialise as the actor was busy with other projects.
Karthik Subbaraj, who has directed South superstar Rajinikanth in Petta, believes the film strikes a balance between content and star power.
The director said if the big names keep the script on a back burner, the film will not work eventually.
"You need actors and performers, but there has to be content in a film. I don't think stardom will fade away. If a star film does not have a good story, it will not run. This will make stars choose good scripts consciously," Karthik told PTI.
The director said this is the first time that he has written a story for a star, whom he admires a lot.
"Usually, I write my scripts first then think of the actors, or I have a reference of someone. This is the first time I wrote for a hero," he said.
Rajinikanth's last few films have not broken the box office records, as they are known to do, but the filmmaker said this was not something that he worried about.
"There was no worry. The makers are not worried. There is no effect of all that," he added.
Karthik said he had first run the idea past Rajinikanth four years ago, but things did not materialise as the actor was busy with other projects.
"I met Rajini sir after 'Jigarthanda' and he said he liked my film. He told me I could approach him whenever I had a good idea. I had never thought he would listen to scripts from new directors. After the meeting, I wondered: 'Should I take his words seriously or not? Should I write something'?
"The announcement of 'Kabali' with Pa Ranjith gave me a push that he is willing to work with new filmmakers. After that, I started writing a script for Rajini sir," he said.
Karthik said he had barely begun the preproduction on his next film, starring Dhanush when Rajinikanth showed interest.
The director said he decided to put the film on hold as this was an opportunity to work with his idol.
"I discussed this with the team and we decided to push it for a year. The team, including Dhanush, understood that this is the big opportunity for me as a director," he added.
In "Petta", Rajinikanth plays the role of a college hostel warden.
Karthik said the film is based on the relationship between the superstar's character and the students.
"How he deals with the situation after an issue comes up is the plot. The trailer of the film has trademark Rajinikanth moments - from the way he flips cigarettes to wearing his sunglasses.
Karthik said he consciously kept those whistle-worthy moments in the script.
He added, "I wanted to show his style on screen. I wanted to watch it on screen. I was not only a fan but a director too who was watching his idol performing. Every moment was great."
Also featuring Nawazuddin Siddiqui, the film releases Friday.
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