 He was later invited to join the Academy of Motion Picture Arts and Sciences.Arndt began collaborating with Lee Unkrich and other Pixar personnel on the screenplay for "Toy Story 3" in 2006, working from a treatment by Andrew Stanton, who co-wrote the two preceding films in the series.He was nominated for Best Adapted Screenplay for his work for "Toy Story 3", and became the first ever screenwriter to be nominated for both Academy Awards for Best Original Screenplay and Best Adapted Screenplay for his first two screenplays.