A source tells PEOPLE says that Pitt, 54, has spent time with his friends recently and is in great spirits.
“He seems like a better version of the old happy Brad,” the insider says. “He looks like he has aged in reverse. You can tell he is taking better care of himself. He also seems very positive about the future.”
The film tells the story of an actor and his stunt double who make a name for themselves in Los Angeles during the 1969 Charles Manson murders.
“Brad filmed a few scenes earlier this week in L.A. and the set vibe has been amazing,” a source familiar with the set tells PEOPLE. “Everyone is excited to work with him and Quentin. Of course Quentin is demanding to work with, but also fun. Brad has been great.”
“Some of the set worked with him before, so Brad made sure to say hello to familiar faces,” the source adds. “He is very professional and friendly. Everyone calls him Brad. It’s been clear that he just wants to shoot the best movie possible. He has been all about work and seems very happy about filming.”
Pitt’s been spending more time with his children, as well. Earlier in June, a judge presiding over the actor and Angelina Jolie’s divorce proceedings established a detailed schedule for the actor to spend time with Pax, 14, Zahara, 13, Shiloh, 12, and 9-year-old twins Vivienne and Knox, who reside with Jolie as she films Maleficent 2 in London. The kids normally reside in Los Angeles with Jolie, where Pitt also lives.
The court papers obtained by PEOPLE stated, “the children not having a relationship with their father is harmful to them,” and that Jolie, 43, could lose full custody of the kids if she doesn’t allow them to grow their relationships with Pitt.
Maddox, 16, their oldest son, isn’t included in the timetable. That’s because, according to the court, Maddox is old enough to decide for himself how much time he wants to spend with his father.
“It’s been obvious that he has been missing his kids like crazy,” a source previously told PEOPLE. “To live so close to them, but not seeing them often, has definitely been painful for him.”
“There has never been a set schedule. It all seemed very strange and unorganized,” the source added of the couple’s previous custody arrangements. “Brad was always an amazing dad. The kids have always been his life. He has flaws like most people, but so does Angie. Brad must be so relieved that the court is now helping him.”
RELATED: Angelina Jolie Could Lose Primary Custody of Kids If Brad Pitt Isn’t Allowed Access: Report
Pitt was able to celebrate Father’s Day with the kids in London, where he was seen riding his bike across the Coworth Park hotel property, only a few miles from where Jolie and the kids stay in England.
Now that filming has started on Once Upon a Time in Hollywood, Pitt will balance his time between London and Los Angeles.