Hello all, I’m planning to make a magic character that has glowing tattoos which appear on the arms of the player as a spell is cast. Ideally, the tattoo would be different for each spell.
I was wondering if decals are the way to go to achieve that effect?
Thanks in advance!
Yeah you can do that in different ways…
Like you can use mask texture to apply on specific uv and change that mask runtime… or you can use decals too…
But i think the best option to use mesh decals if tatoos always appaers on same position…
With mesh decals you will got a whole material which can be procedural, dynamic, can work by masks… and you do not worry about attaching to mesh, move them, replicate them etc. 
Take a look: Mesh Decals | Unreal Engine Documentation