File Extension VTX File Format Steam source SDK compiled model file VTX stands for Steam source SDK compiled model file. This was last updated in March 2012 By Margaret Rouse Browse File Extensions Alphabetically: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z # Ask a Question. Find an Answer. Ask your peers a question about this file extension. Ask a Question How do SDK updates affect development timelines? Gaming as a service -- GaaS How to get data from biometric to VB6?