This application is used to create copies of *.vtx files and change their extension to .dx90.vtx or similar. The first command line argument is a path to a dirrectory. This directory and all subdirectories are seached for *.vtx files. For each .vtx file a copy is created and its file extension is changed to .dx90.vtx. The second command line argument is optional and can be used to specify the extension for the copied file to use. E.g. you may specify .dx80.vtx extension if you need *.dx80.vtx files.