Earlier this month we learned that Katy Perry would be releasing a 3D concert film (we expect it to be similar in style to Justin Bieber’s Never Say Never).

Yesterday, Twilight stars Robert Pattinson and Kristen Stewart were spotted on set.

The concert film, titled Pieces of Me, will be based on one of Perry’s live shows, but is to include a backstory on the singer’s life.

No word yet on why the Twilight stars were there. It may have been business or simply pleasure.

Thanks to Hollywood Crush.