Just Like Rays Mod FAQ

Yes. After adding Just Like Rays Mod to your world, go to Edit World > Optimize World > Erase Cached Data to refresh all light calculations. Without this step, old lighting data will remain and you won't see the realistic ray-based shadows.

You likely haven't optimized your world yet. The mod requires you to erase cached lighting data for the changes to take effect—simply loading the world isn't enough.

Yes, the mod works independently of shaders. Since it changes how light actually spreads in your world files, you'll see realistic shadows even without a shader pack, though you can use both together.

Light recalculates to account for the new block placement or removal, casting shadows accordingly. If light doesn't update immediately after building, try re-entering the chunk or using Optimize World again.

Yes, the mod runs server-side, so only the server needs it installed. All players on that server will see the realistic lighting without needing the mod themselves.

The mod changes how the server calculates light, which may have a minor performance impact depending on your world size and complexity. The effect is typically negligible on modern hardware.

Yes, significantly. After optimizing your world, all existing light from torches, lanterns, and glow blocks will now spread in realistic rays and cast proper shadows. Caves and bases will look dramatically different.

Yes, stairs and partial blocks cast accurate shadow shapes based on their geometry, unlike vanilla Minecraft where light treats them as full blocks.

The mod affects all block light sources including torches, lanterns, glow lichen, and other luminous blocks. Sunlight also casts realistic shadows from solid structures.

You can remove the mod, but your world's lighting data will remain changed. If you want to revert to vanilla lighting, you'd need to restore from a backup made before installing the mod.