It's just a shader, converted from GLSL to HLSL. Unfortunately I don't have enough knowledge, to change/adapt this code, in order to use it with real level environments, but I hope it's possible. These shaders reminded me of a project, made by Hummel (if I'm not mistaken), he made 2D shadows demo back in the times, but you had to place walls by yourself, in order to get shadows and it only could be used in 2D. I think it's the same thing here too, those shaders need some work to get them working in 3dgs.