I am currently working on some title work in AE. The text is slowly moving away from the camera and I need to add some blood splatter that only surround the text area. I have tracked the motion and rotobrushed the text. However the rotobrush only masks out the background of the layer with the title. Is there anyway to get this mask applied on the layer with the blood splatter?
Use it as a track matte. May require pre-composing.
Track matte is the easiest and most efficient way. You can duplicate the layer and replace footage but that would double the load on the system that rotobrush already imposes. I'd go with a track matte. If the shot is more than a few seconds long then I'd render the rotobrush layer using the Lossless With Alpha preset in the Output module making sure that the color was changed to Straight Matte, then import the footage and replace the layer with the footage and use that as a track matte. In many if not most cases this will save you time in the long run.