Paul Walker Was the 'Happiest He'd Ever Been' as a Dad

He may have been a movie star, but friends say the role Paul Walker cherished most was Dad.

At the time of his tragic death on Saturday, the actor was living with daughter Meadow, 15, full time and loving every minute as an involved father.

"He told me recently he was the happiest he'd ever been," close friend Brandon Birtell tells PEOPLE. "It was directly because of the growing relationship with his daughter and the clarity that brought to his life."

In her younger years, Meadow lived in Hawaii with her mother, and Walker’s onetime girlfriend, Rebecca Soteros. His own schedule meant constant travel from his California home base, but Walker's little girl was never far from his heart. "It really affected him that he missed time with her in her early years because he was working," Walker's longtime manager and close friend Matt Luber tells PEOPLE. "It was a struggle for him. [When she moved to California], he wanted to make the most of every single moment with her. He was completely dedicated."

In fact, despite the fact that the free-spirited Walker "liked the freedom of having no roots, she was the only thing he couldn't stand being away from,” adds Birtell. So much so that Meadow and her dad would coordinate schedules to provide for ample father/daughter time together. Shares Britell: "Paul told Meadow he didn't want to take a particular movie because he didn't want to be away from her. [Meadow] asked where it would be shooting and he gave her the dates and said, 'Overseas.' She thought for a minute and said, 'That's during my summer vacation. We can do that.' "

With news of the star's passing, the Fast & Furious 7 actor's cast mates will halt filming the latest movie in the hit franchise.

"Right now, all of us at Universal are dedicated to providing support to Paul's immediate family and our extended Fast & Furious family of cast, crew and filmmakers," Universal said in a statement obtained by PEOPLE on Wednesday.

"At this time we feel it is our responsibility to shut down production on Fast & Furious 7 for a period of time so we can assess all options available to move forward with the franchise. We are committed to keeping Fast & Furious fans informed, and we will provide further information to them when we have it. Until then, we know they join us in mourning the passing of our dear friend Paul Walker."