.LLM files are Linden Lab Mesh (LLM) files that are used by Second Life, which is a network-based virtual reality world. LLM files contain a 3D "mesh" definition which is a collection of polygons that form the surface of an avatar. The LLM file is used to render a custom 3D avatar and create texture wrappings. LLM files may be created in base format or level of detail (LOD) format. Base format meshes contain the original mesh definition, while LOD meshes contain alternate meshes in a decreasing resolution that are use to display the avatar when it is far away from the camera. LLM files may also be called Linden Binary Mesh files.