The Source Filmmaker is the movie-making tool built and used by Valve to make movies inside the Source game engine. It is how we have been making all of our animated short movies. Because the Source Filmmaker uses the same assets as a Source-engine game, what goes into the game can be used in the movie, and vice versa. By using the hardware rendering of a modern PC gaming machine, the SFM allows storytellers to work in a “what you see is what you get” environment so that they can iterate in the context of what it will feel like for the final audience.