Pascal Gilcher, also known as Marty McFly, has just rolled out what he calls the ‘biggest update yet’ for his popular RTGI ReShade shader. 
After six months of silence, the new version is now available exclusively to his Patreon subscribers, and it’s packed with improvements.
Originally, Gilcher attempted to incorporate the ReSTIR GI algorithm into his shader. However, he quickly ran into some significant challenges, such as chroma noise (because the reservoir sampling method could only capture light from a single direction), sample correlation issues that disrupted denoiser variance estimation, and white noise output. These issues led him to develop his own sampling algorithm, which he claims far outperforms ReSTIR GI in terms of quality.
In addition to the improved sampling algorithm, the RTGI shader also boasts significant upgrades to its reflections. These now follow pixel-perfect paths thanks to HiZ Min-Max Tracing, ensuring a more accurate and lifelike visual output.
Looking ahead, Gilcher has outlined plans to split RTGI’s diffuse and specular components into separate shaders
. This change is intended to make managing these elements easier and more flexible for users. Furthermore, Gilcher’s other shaders have received improvements, particularly the MXAO shader. The notorious low-radius halos around objects have now been fixed, delivering a cleaner look.
Another significant update comes with Launchpad, a shader that incorporates optical flow used by various other shaders. The latest version introduces a new gradient descent-based algorithm, which is designed to handle subpixel shifts more efficiently compared to traditional grid-based search methods. Users can now select between two gradient descent optimizers: Newton, which converges quickly and is best for lower-quality settings, and SophiaG, which converges more slowly but finds better minima, making it ideal for high-quality settings.
In addition to these updates, Gilcher has introduced a brand new shader: the path-traced volumetric fog. Initially created as a reference for a real-time effect, Gilcher found it so impressive that he decided to make the full path-traced version available for beta testing. However, it is currently only accessible at the highest Patreon tier, ‘Photon Mappers,’ priced at $20 monthly. The shader, designed for screenshots, can be seen in action in the game God of War.