If you find the setup for Pascal Gilcher’s RTGI too complex, look into which is often included for free in standard ReShade shader packages like Quint or AstrayFX . These provide a very similar "pop" to the visuals without needing a Patreon login.
While not as advanced as a dedicated RTGI plugin, the latest versions of ReShade include "Screen Space Ambient Occlusion" (SSAO) and light-bouncing effects that mimic the look for free.
To use an RTGI shader, you first need , a generic post-processing injector.
RTGI Shader Free Download: How to Get Ray Traced Global Illumination in Any Game
While the most cutting-edge versions of the "Marty McFly RTGI" may require a subscription, older versions or community-made alternatives often circulate as free downloads on official modding forums. How to Install RTGI Shaders Using ReShade