Machinima, a Portmanteau of machine cinema, is a collection of associated production techniques whereby computer-generated imagery (CGI) is rendered using real-time, interactive 3-D engines instead of professional 3D animation software. Engines from first-person shooter and role-playing simulation video games are typically used. Consequently, the rendering can be done in real-time using PCs (either using the computer of the creator or the viewer), rather than with complex 3D engines using huge render farms. Usually, machinima productions are produced using the tools (demo recording, camera angle, level editor, script editor, etc.) and resources (backgrounds, levels, characters, skins, etc.) available in a game.