How to paint material where actor moves?

Simply put, I am trying to figure out a way to paint a material/texture wherever an actor steps, like a trail. After a certain amount of time, that texture would revert to whatever it was before the actor moved over it. I haven’t the faintest idea how to go about this, any ideas?

Hi Aggroed,

The best way I’ve found to do this is by using a trail of decals. Decals project a material (which can have a texture) onto the ground, so that you don’t have to mess with the actual texture of the ground. Keep in mind that decals only project in one direction & need to be close to the surface of projection.

  1. Create a decal material with the texture that you want.
  2. Spawn a set number of decals into a queue depending on how long you want the trail.
  3. Update the location of the next decal in the queue each tick so that you don’t have to keep re-spawning new ones.
  4. Optional Run a timeline animation for interesting effects like growing and shrinking