Wisps are a non-entity, flame-like mob. They spawn near trees and can be caught with Jars. Catching them is not easy, as they will flee when a player is too close and can phase through solid blocks when chased.
After being caught with a Jar, the Jar can be placed and will provide benefits to the environment around them.
Red Wisps in Jars will destroy all plants in a 10x10x10 area, making them useful for keeping weeds away, but also dangerous to gardens.
Green Wisps in Jars will accelerate growth of plants in a 10x10x10 area, there is no constant rate, so it may take the plants no longer than usual to grow, or they could fully grow within seconds.
Blue Wisps in Jars will prevent fires in a 10x10x10 area, making them useful for protecting flammable builds.
If you want to spawn a wisp, use the /add_wisp command. You can specifiy a color(red, green, or blue), but if you don't a random color will be picked.
If you want to clear all wisps (excluding those in Jars), use the /clear_wisps command.
This mod is W.I.P, and will be taking the back burner as other projects are more important.
I like the premise, but I have a few ideas on what you can do to make it better.
I love the green wisps, but I have also noticed the lag capabilities of the wisps. Perhaps consider making it so that whenever the world quits, despawn all wisps not in jars, like:
So, running, in this example, freewispwipe instead of save in: minetest.register_on_shutdown(freewispwipe)
Also, it gets annoying trying to chase down the wisps when they get too high or too low. Would it be possible to make the wisps first try to flee if a player is too close (which it already does), then, if no player is nearby, start trying to approach nodes from group:tree? It would make sense for them to approach the source of their creation when they are left alone.
I don't know how to code that, sorry. I tried, but each time I tried it seems to have trouble as soon as the wisp stopped being too close to you, the game crashed.
Adds life to your worlds
The wisps just fly around and look good. I like the ability to prevent fires and easily clear grass. But be careful because you might get lag. I had a base next to huge trees and I got strange lag as soon as it was getting dark because there spawned an insane amount of wisps under the trees. After disabling wisps, the lag disappeared.
You can even invent mini-mechanisms