UE4. Rendertarget2d from geometry to (with) specific UV

Hi guys

Im firstr time try rendertarget’s so need a little help.

What i need:
Specific geometry with specific UV
Those geometry will have specific material
Rendertarget2d should give me result of that material relay on that object UV

I hope that image should explain what i really need.
So i do some raytrace to object, and distance(worldposition, trace impact point) and take a sphere mask from that.
Render target should be, as example, black, with white areas which are marker red in the UV screenshot.
Probably the easiest way to explain this -> It should work like when you draw on you model in Substance Painter. You paint on you model and its appear in you UV square in respectively UV islands and so on.

Currently im dont even know is that possible with default UE4 BP and rendertarget system?