This is the ONLY option that I know of and use myself. You must have a mac to set it up. You need to go into quartz composer while you have your cameras plugged in. open a video patch and set it to one of your cameras and save the project as Camera one. now in the same patch change camera to the second and save patch as camera 2. do this for all your cameras and save with different numbers. open resolume and drop all patches in different layers and you have multiple cameras.
IMPORTANT!!!!!!!!!!!!!!!!!! If you use a MAC, you MUST use cameras that can be used on a LINUX machine. Creatives work. I do not know how cameras work on pc though.