His death, of acute mixed drug intoxication, rocked his co-stars and colleagues.
"It was about as horrible a thing that can happen. It was just completely tragic. It threw us all," director Francis Lawrence told Vulture. "There were two substantial scenes that he had left, scenes with dialogue. All the other scenes he had were appearances in scenes where he had no dialogue."
Hoffman, who was 46 at the time of his death, played Plutarch Heavensbee in the franchise films -- a role he originated in "The Hunger Games: Catching Fire." Recreating him digitally was never even a consideration, Lawrence said.
"We decided to rewrite the scenes and give his dialogue to other [actors]," he explained. "There's a scene in 'Mockingjay Part 1' that Elizabeth Banks took over for, and there's a scene in 'Mockingjay Part 2' that Woody Harrelson took over for."
Still, the loss of Hoffman created deep sense of sadness for everybody working on the project. Going to work became difficult.
"It was a really tough, emotional time," he said, "and tough getting back into work and trying to find a groove again."