IterationVX – Ray-Traced Colored Block Lighting
SHADERRay-traced colored block lighting for Iris: every torch, lamp and glowing block emits its own colored light and casts crisp ray-traced shadows and reflections.
IterationVX solves the flat, monochrome lighting that vanilla shaders and most path-traced packs leave untouched. It adds real-time voxel-based ray tracing for every block light in your world — torches, glowstone, soul fire, candlesticks, sea lanterns, froglights, lava, and anything else that glows. Each source casts its own color onto nearby surfaces, throws crisp shadows behind solid blocks, and reflects in polished materials with correct hue. All of this runs inside Iris and Oculus as an edit of IterationT 3.2.0 (Chocapic13), borrowing the approach of Rethinking Voxels.
This shader is made for builders, map makers, and anyone who wants light to behave like a real-level design tool. Underground spaces feel vibrant with multi-colored glowstone and soul-fire corridors, while stained glass windows properly tint the light passing through them. Water filters sunlight into cool blues, and specular highlights appear exactly where you’d expect on metal and concrete. Because the system tracks only block-level emitters, outdoor scenes with no placed lights see almost no added cost — the ray marching only activates near painted blocks.
- Per-block colored light — glowstone, sea lanterns, soul fire, amethyst, froglights, candles, lava, and more emit their own color, auto-detected from the texture when not explicitly defined.
- Ray-traced shadows — torches and lamps cast hard, pixel-accurate shadows from a 128×96×128 voxel volume surrounding the camera.
- Ray-traced specular reflections — lights reflect off smooth surfaces with correct color, and those reflections obey shadows.
- Tinted translucency — light passing through stained glass, water, or ice picks up the tint of the material, turning blue underwater or red behind crimson glass.
- Deterministic falloff — light decay follows IterationT’s vanilla curve exactly (normalized modulation), so you never see visible rings or unnatural cutoffs.
Requirements: Iris 1.6.4+ or Oculus with a compatible GPU that supports the shader pipeline. You need the base pack IterationT 3.2.0 installed first — IterationVX is an edit that runs on top of it. The voxel volume is fixed at 128×96×128 blocks; lights beyond that range fade naturally but won’t cast shadows. Performance scales with the number of nearby block lights, so dense torch arrays in a small area will push the GPU harder than a single lantern. Distant Horizons works with the active voxel system, so far terrain renders correctly.