I am currently trying to change an assets material to an emissive texture when touched by a sonar which fires out from the player location, I am just wondering if there are any methods of doing this, any help will be greatly appreciated, thank you.
You might want to take a look at Dynamic Materials at https://docs.unrealengine.com/en-us/Videos/PLZlv_N0_O1gbQjgY0nDwZNYe_N8IcYWS-/srUSDU1u0og
You can set the actors in your scene to have dynamic materials and then add an event to change some material parameters to get the effect you want.
Then you just have to wrap this in an event and call that event when collision overlaps begin/ends etc…
This will require a bit of work in material editing, and if you plan to have all actors in your game support this mechanic you might want to wrap some common dinamic material parameters in a master material that you use as a base for all your materials.