What Is an MAT File?
A file with the MAT file extension is most likely a Microsoft Access Table Shortcut file that’s used to quickly open a table without having to first open the MS Access program. The MathWorks MATLAB program uses MAT files, too, but as a container for holding data like functions and variables. This file extension is also used in 3D design software to denote a file that stores things like textures and images. These are called 3ds Max Materials files, Vue Material files, or V-Ray Materials files.
How to Open an MAT File
MAT files that are Microsoft Access Shortcut files can be created by dragging a table out of Access and to the desktop or into another folder. Microsoft Access needs to be installed in order to use them. MATLAB from MathWorks can open MAT files that are used by that program. If your file isn’t in either of those formats, it might instead be a materials file used in 3D design software. Autodesk’s 3ds Max and E-on Vue use MAT files. Chaos Software’s V-Ray plugin can load one into 3ds Max and MAXON CINEMA. The Unity game engine may use files with this extension as well. Use a free text editor to open it if none of the above programs are working for you. It’s possible that a different program created it and stored the information in a plain text file. This isn’t the case for any of the above cases, but it might be for yours.
How to Convert an MAT File
There’s no way to convert a Microsoft Access Table Shortcut file, and there’s also probably no reason to want to convert this type of file. However, materials files probably can be converted. This is likely possible through the program that uses the file. So if you’re wanting to convert one that’s used with E-on Vue, for example, you should be able to open the file there and save to another format. This is normally possible though a Save As or Export option in the File menu. You can convert 3ds Max Materials files to a format that’s supported by previous versions of the software. MATLAB can convert MAT to CSV. See the instructions at MATLAB Answers if you need help, as well as this documentation on csvwrite. Follow that same MATLAB Answers link to search around the site if you need help converting MAT to TXT or another text-based format.
Still Can’t Open It?
MAT files aren’t the same as MATERIAL files, which are Rigs of Rods Texture Reference files used with the Rigs of Rods 3D simulator game. Atomic Combat is another game that uses a similar extension of .MATO for saved game files, but they are used with that game, specifically. Despite those file extensions looking like they’re related to MAT files, they’re actually in their own format and therefore open with their own programs.