Plese help to create custom top-down light?

i have a scene with obstacles and character. Character has one point light. This game is mobile first so i want good frame rate but unity light is too heavy for most mobile devices. I used raytracing script. it creates mesh that represents lit areas. I have one problem: how another meshes can check intersection from shader to know is that meshes lit or partly lit. Or are there any other ways to achive good light on mobiles.

I used stencil buffer but it doesnt seem to work.

P.s. my game is TOP-DOWN 3D and not 2d.