if you set the texture display to rendered you get the work window to show the mats as you alter them, that can be a bit slow if the window is "full size" depending on ur comp lol, since I use twin monitors I have a small window on second set to rendered (also have my node window on that screen ) does make it a lot of fun when u grab a light an drag it round in scene and see what its doin in little rendered window,  hope that helps but I'm not sure its what you was asking rofl