What is the R-T-S Shader? It is a shader pack that attempts to simulate complex global illumination techniques. Unlike traditional shaders that rely on simple rasterization, R-T-S calculates light paths more realistically within the game engine. A vanilla-like pack by eiden featuring shadows, tuned for low-tier hardware and better. Compatible with Iris and OptiFine across Minecraft 1.20.1 – 26.2. Licensed Apache-2.0, so the download is mirrored right here on MineSpecs — no ads, no redirects.

How to install R-T-S

1. 1Install a shader loader for Minecraft 1.20.1 – 26.2 — Iris (pairs with Sodium) or OptiFine.R-T-S is a shaderpack, so it needs a loader to run.
2. 2Download the R-T-S .zip from the button above — keep it zipped. It is mirrored on MineSpecs, so there is no ad-gate or redirect.
3. 3Drop the .zip into your .minecraft/shaderpacks folder (%appdata%\.minecraft\shaderpacks on Windows, ~/Library/Application Support/minecraft/shaderpacks on macOS).
4. 4Launch the game, open Options → Video Settings → Shaders, and select R-T-S.

Performance & what to expect

R-T-S is rated low performance impact. It is comfortable on entry-level dedicated GPUs at a normal render distance. It renders shadows.

More low-impact shaders

MakeUp — Ultra FastLow impact · by KDXavierRenderPearlLow impact · by LuracasmusBVS — Best Vanilla ShaderLow impact · by LoLip_pCursed FogLow impact · by LoLip_pOpenShadLow impact · by WavinGraphicsBlocky ShaderLow impact · by dvimidh

R-T-S is created by eiden and mirrored here under its Apache-2.0 licence. MineSpecs is an unofficial fan project and is not affiliated with eiden, Mojang Studios or Microsoft.