Got it, thank you! I was asking because using DRR command in the “Plastimatch Command Prompt” on a PC yields a .pfm and a .txt file that contains the projection matrix that Andras mentioned in his last post.
I would like to figure out a workflow that is primarily within 3D Slicer, so I am trying to figure out the best way to obtain this projection matrix through 3D Slicer. I thought that outputting a .pfm or .pgm from the DRR Generation module might create a file on my local hard drive with the accompanying .txt.