Firmament 0.21

A cleaner shader core and a faster sky, with the same look.

• Sky: the atmosphere pass computes the sun and moon once per frame instead of once per pixel and is about 1.3× faster by day and night.
• Fog and light shafts: 1.06–1.17× faster above and below water.
• Night sky: stars and clouds over open sky about 1.06× faster; ambient occlusion reconstruction about 1.03×.
• Under the hood: shared shader code is reorganized, with named materials and one implementation of each lighting helper. Every other pass costs the same as in 0.2.

The figures are isolated GPU pass timings measured against 0.2 on an RTX 4060 Laptop GPU at 2560 × 1440 with the High preset, not frame rates. In-game FPS depends on the scene, render distance and hardware.

Rendering, presets, options and the 29 supported Minecraft Java versions are unchanged from 0.2: 1.18.2; 1.19, 1.19.1, 1.19.2 and 1.19.4; 1.20–1.20.6; 1.21–1.21.11; 26.1, 26.1.1, 26.1.2, 26.2 and 26.3. Automated OpenGL comparisons match 0.2 within the project's equivalence limits.

Known: after reloading chunks with F3+A, shadows of blocks outside your view appear once you look at them. Iris only builds chunks the camera sees.

Use the Iris and Sodium builds matching your Minecraft version; 26.2 and 26.3 target the OpenGL renderer. Recorded gameplay evidence remains 1.21.1 / NeoForge 21.1.228 / Iris 1.8.12 / Sodium 0.6.13 with 0.10-alpha.2.

Keep the ZIP intact, place it in shaderpacks, and select Firmament in Iris. Start with High and adjust the preset for your setup.

A project by PozziTiv4ik.