As the format name suggests, files with the PRJ extension are used to store data regarding a certain project. They're created with Autodesk 3ds Max, an application used for developing complex 3d animations and models for video games, movies and for television.

The information contained within PRJ files includes user settings, links to other files and everything about the animations and models of the project. This includes lighting data, vertices information, mapping parameters, mesh data, image references, material attributes, etc.

How to open PRJ Files

PRJ files are opened in Autodesk 3ds Max. When importing them the user can choose to merge the stored data with the current scene or to completely replace the current scene. If the PRJ file contains 3D animation the user will be asked whether he wants to change the length of the animation in the scene to match the one of the PRJ file.

Also, when importing a PRJ file in 3ds Max users can choose to import shapes as single objects or as multiple objects. If imported as single objects, all polygons in the PRJ file are converted to Bezier splines and stored inside a composite shape object. If the "multiple objects" option is chosen, the polygons are stored inside an independent shape object instead.