In computer graphics, 3D objects are stored in files that are meant to be loaded and displayed on the screen. Although multiple file formats exist for 3D models, OBJ is one of the most commonly used. These files are plain text ending in .obj that contain the following: A list of vertices that specifies the x, y,z coordinates of each point in 3D space A list of faces, each of which specifies the index number of three points that form a triangle Each vertex is listed on one line, and begins with the letter v. The x, y, and z coordinates are included next, separated by spaces. After all the vertices are done, each face is then listed on one line beginning with the letter f. The three index numbers are included next, starting with 1, also separated by spaces. For example, this OBJ file contains a single triangle.