Mapping FAQ - coloursofnoise/Resources GitHub Wiki
To make maps, you must have Everest (the mod loader), and Ahorn (the map editor) installed. Both of these can conveniently be installed using a program called Olympus. For up-to-date Ahorn documentation, including installation information, see https://github.com/CelestialCartographers/Ahorn.
Control and S.
Alt and Delete.
Click Room at the top, and then Add.
If you know how to program, use Maple. Ahorn will likely not have a GUI macro system, but Maple is quite simple for programmers.
There isn't a set schedule, but generally every 3-6 months. Don't complain if there isn't one.
Add one player entity per room entrance / exit.
YourMap.bin + YourMap-B.bin
You'll need to collect each heart in every A and B side in the levelset and complete the side at least once, or use cheat mode.
See the Stylegrounds tutorial here.
Ahorn will find it if you place it in Celeste/Mods/YourMod/Graphics/Atlases/Gameplay/decals/author/decal.png
Filenames ending with numbers will be used as animation frames by Celeste; Ahorn hides all of these frames besides the first frame (00) so the decal list is not cluttered.
If it doesn't show up in your decals list, even after refreshing it, try to restart Ahorn.
.bin maps are not recommended for public distribution, and it is recommended to use a .zip instead. If you would like to convert them automatically, you can use Postcard.
Postcard can do this automatically. Simply upload your screenshot, hit submit, and save the new image. Please report issues to @leo60228#0480 on Discord. If this doesn't work, manual instructions are also available on the Map Metadata page.