PathMax

PathMax is a path traced shader pack for Iris that lights the world by tracing rays through a voxel grid rebuilt every frame. The look is realistic and atmospheric with fantasy touches, and Modrinth files it under the medium performance tier. It runs on your own machine only.

Shader loaders and versions

• Iris: Minecraft 1.20.1 to 26.3.

Lighting and atmosphere

A torch lights a room from the direction it actually sits in and casts a real shadow. Colour bleeds off the block a ray bounced from, and a lava lake lights the ceiling above it. Two lamps in one room stay two lamps, because each block light gets its own shadow ray.

• Path traced global illumination, denoised in screen space.
• Coloured light through stained glass, on the floor, in the air and carried by the bounce.
• Volumetric light and volumetric clouds, with clouds visible in reflections.
• Light pollution from distant towns, procedural stars and height-based aerial perspective.
• AgX tonemapping by default, with ACES and four other options, plus auto exposure, bloom and optional TAA.

Water, materials and dimensions

Reflections are screen-space, so water shows the finished frame with its lighting, fog and emission. Water adds refraction, foam and caustics, with optional waves and volumetrics above and below the surface. Materials use labPBR with a built-in fallback for packs that ship no specular map, plus subsurface scattering for foliage and optional parallax occlusion mapping. Mobs are voxelised, so they cast traced shadows.

The Nether and the End are rewritten rather than tinted. There is no phantom sun, and ambient light arrives from the floor where the lava is. Block shapes and material handling are current to 1.21.4, and newer blocks still render without the special treatment.

Profiles and settings

Seventeen settings screens document every option in its tooltip. Five profiles run from Potato to Ultra as one ladder. The cheap end saves by dropping volumetrics, clouds and reach, and the expensive end spends on rays first. The pack ships with a night-heavy hand-tuned configuration, so pick Balanced for the reference settings.

Installing PathMax

1. 1.Install Iris, following the shader install guide.
2. 2.Put the PathMax .zip in the shaderpacks folder.
3. 3.Open Video Settings, then Shader Packs, and select PathMax.
4. 4.If the pack fails to load, work through the shaders not working guide.