How do I turn on the light level overlay?
This is a core shader, so you switch it on from the in-game Resource Packs menu rather than through a mod loader. Move it into the active list, apply it, and the light markings will show up on the blocks around you.
Do I need Forge or Fabric for this to work?
No. It runs directly in standard Minecraft without any extra mod loaders.
What do the 0, 1 and 15 markings mean?
Light Level 0 marks the darkest blocks, where hostile mobs spawn. Light Level 1 marks blocks with very low light, which are good places to add torches. Light Level 15 marks the brightest spots, such as blocks right next to a strong light source.
Which blocks should I worry about for mob spawning?
Focus on blocks marked Light Level 0, because that is where hostile mobs spawn. Clear every 0 marking from an area to stop zombies and creepers from appearing there.
How do I use this to make my base spawn-proof?
Walk through your base and outer areas looking for Light Level 0 markings and place light sources until they disappear. Then check any Light Level 1 spots, since they show where the light is only just reaching.
Why can't I see any light numbers after turning it on?
Make sure the pack is in the active list in the Resource Packs menu and that you clicked Done to reload. If another resource pack or shader also changes the game's core shaders, it can override this one, so move this pack to the top of the list or disable the conflicting pack.
Why don't I see markings on every block?
The overlay is built around three light levels: 0, 1 and 15. Blocks at other light levels won't have these highlights, so missing markings in an area usually just means its light falls between those values.
Will this lag my game?
It's designed to be lightweight and uses very few computer resources, so your game should keep running fast. If you notice slowdowns, check whether other heavy resource packs or shader mods are running alongside it.
Can I use this on a multiplayer server?
Yes. It only changes how the game looks on your own screen, so it runs on your client and the server doesn't need to have it.
Does it work together with other shader packs?
Other packs that also change the game's core shaders can conflict with it or cover up the light markings. If the markings vanish when you add another pack, disable that pack or change the load order so this one takes priority.