Basically, jabelar's Moving Light Sources but for 1.15.2 (no code was copied and the technique used is different)

This mod replicates the features found in most lighting mods like Optifine where non-block items give off light. However, unlike those client-side rendering mods, Portable Light Sources no produce real light. this means blocks and mechanics sensitive to light will respond correctly. It is also not a "core mod" which means it is compatible with shaders and other lighting changes.

Features

- Items such as Torches and Sea Lanterns with a block that gives off light emit light at the same brightness level

- Items, where it makes sense to emit light, do now eg. Blaze Rod

- Those same items give off light when thrown

- Flaming entities, including arrows, give off light

- Entities like Blazes give off light naturally

Example

This is my mod working in conjunction with a work in progress that adds a glowing sword (you'd think it would be easier than it was)

FAQ

Q: Will this lag my game?

A: Hopefully not. You'll get lag spikes when loading new chunks and when you start the game because the mod registers entities. I've made lots of changes to optimize the speed but this will never be a fast mod. One optimization made prevents entities that would catch fire in any normal circumstances from emitting light (eg. cod, minecart, dolphin). If there is enough interest from people with beefy computers I can whip together a config file to re-enable those entities but it was just too costly for normal use.

Q: Is this compatible with other mods?

A: Should be 100% compatible.

Q: Does this support items/mobs from X mod?

A: Not in the slightest, however, a patch is really easy since very little is hardcoded.

Known Issues

- Firing too many flaming arrows onto the same block sometimes causes a glitch where even after collecting the arrows, the area remains lit. This can be remedied by placing a block on the lit area then mining it.

~~- Using a spawn egg to create a Blaze or Magma Cube causes the same glitch as the arrows.~~

~~- Same as above but when firing an arrow will light the block you're at~~

The struck out issues should be fixed in the latest version but there's always the chance my testing wasn't thorough enough.

- Small visual anomaly sometimes appears when throwing an item light source when its dark (not even sure if this one is a glitch but I'll try to make it not happen)

- If you are surrounded by a block like cobwebs that you can walk through your light will go out. This is because there isn't any air nearby. I could fix it but it would require me to reimplement every block you can walk through and that's not something I want to spend time doing (it would also lag the game to a halt.)

If you get any of these bugs send me your logs so I can try and fix them.