Randomly placed and fading textures

This tutorial demonstrates how to apply “morphed” wrinkles, using dynamic textures. and for water effect you can also make dynamic texture effects…

I this way you could also add scares to the body/mesh - but I wonder if you could somehow add random bruises that will dynamically fade over time. For that to happen, in a constructive way, i would probably need two things:

  • Having a selection of dynamic textures with their own sizes, life span etc.… say spanning from quickly fading to a more permanent state. ( i guess this is somewhat covered by the tutorial)
  • Some way of calculating a random placement… on the UV map

My question is, can I somehow position such textures so I know that they will be placed somewhere target area (say the face, the legs or on the hands, etc.) … that is, i guess, via my knowledge about the UV?

Adding on this…. from the samples from the above tutorial I made a way to “record-animations”. In a similar way I guess I could make a simple “cursor/pencil” texture and then pan it over the mesh using some control and thus “paint” the areas where you would later want you random wrinkles to appear… but I would rather somehow like to “paint” this on the UV map as I think that would make the process a bit more accurate?

I found some hints about this myself… not exactly easy to figure out what this is called in UE4, but it’s there. can be combined with this and I may get some of the result I wanted.