Shotpacker is an Add-on that uses a special algorithm for packing UVs quite tighter than Blender does it.
The Add-on was released first time in 2017. Today it’s one of the best UV packing algorithms for Blender in my opinion. You get a lot for your money.
Below you see an official example of one of the first results of Shotpacker. The packing time isn’t up to date anymore. Shotpacker is very fast today and pack such islands in split seconds.
I haven’t found an official documentation for Shotpacker. But the tool is not that complex and self explained. You’ll find some docs on the shop page on gumroad.
To get more infos please visit the forum post on Blenderartists: https://blenderartists.org/t/uv-packing/687964
Please visit the Blenderartists website, to ask questions and get support for the tool: https://blenderartists.org/t/uv-packing/687964
Where I get it?