It is possible if you use the custom depth stencil. In blueprints, every actor has a custom depth stencil value which determines what post process effects are used on it. If you have a post process volume, set it to have two materials, have one of those materials just be empty, and then set the value of each material to say 0 and 1, then if you say have the empty set to 0, then any actor that has the custom depth stencil to 0 will have that particular post process material applied rather than the others. Of course, the numbers can be whatever you want that the engine supports, I’m just using this as an example. I haven’t tested this personally and can’t because my computer hasn’t arrived yet (I’m writing this on a very weak laptop). However, it is something you can try out and see for yourself.