Motion capture acting is a challenging task, it requires trained and experienced actors who can highly rely on their acting and imagination skills to deliver believable performances. This is especially the case when preparation times are short and scenery needs to be imagined, as it is commonly the case for shoots in the gaming industry. To support actors in such cases, we developed a mixed reality application that allows showing digital scenery and triggering emotions while performing. In this paper we tested our hypothesis that a mixed reality head-mounted projection display can support motion capture acting through the help of experienced motion capture actors performing short acting scenes common for game productions. We evaluated our prototype with four motion capture actors and four motion capture experts. Both groups considered our application as helpful, especially as a rehearsal tool to prepare performances before capturing the motions in a studio. Actors and experts indicated that our application could reduce the time to prepare performances and supports the set up of physical acting scenery.