Machinima creators have used different methods to handle limited character expression. In the "Halo" video game series, helmets completely cover the characters' faces. To prevent confusion, Rooster Teeth's characters move slightly when speaking, a convention shared with anime. Some machinima creators use custom software. For example, Strange Company uses Take Over GL Face Skins to add more facial expressions to their characters filmed in BioWare's 2002 role-playing video game "Neverwinter Nights". Similarly, Atussa Simon used a "library of faces" for characters in "The Battle of Xerxes". In some cases, some game companies may provide such software; examples include Epic Games' Impersonator for "Unreal Tournament 2004" and Valve Corporation's FacePoser for "Half-Life 2". Another solution is to blend in non-machinima elements, as nGame did by inserting painted characters with more expressive faces into its 1999 film "Berlin Assassins". It may be possible to point the camera elsewhere or employ other creative cinematography or acting. For example, Tristan Pope combined creative character and camera positioning with video editing to suggest sexual actions in his controversial film "Not Just Another Love Story".