Adding Custom Audio

Adding Custom Audio

• Setting Yourself Up
• Creating Banks
• Custom Sounds

Setting Yourself Up

You'll need:

• FMOD Studio 1.10.* (Don't use FMOD Studio 2.*, as it is incompatible with Celeste and will break projects made in 1.*. Also note that despite them being labeled as unsupported you can still download these versions, and they should still work fine for you.). You will find it on the FMOD downloads page (you need to create an account, but the program is free).
• The Celeste FMOD project: you will also find it on the FMOD downloads page, in the Learning Resources section. Make sure to read the EULA.

FMOD Studio is compatible with WINE.

ℹ️ Don't modify and share modified music, sfx, ui and master banks.

If you have any further questions regarding audio mods, ask for help in the #modding_help channel on the Discord server.

Creating Banks

Here is a step-by-step guide to create a bank with music you have as sound files:

1. Open the Celeste FMOD project in FMOD Studio: fmodstudio20000celeste-project/FMOD Studio Celeste Project/celeste_audio.fspro.
2. On the left panel, switch to the Banks tab, and create a new bank for your mod. You need 1 bank per mod: if you have multiple tracks for the same mod, you can fit them all in one bank. Name it, for example, yournickname_mapname.

3. Select File > Import Audio Files... then browse to your song. This brings up a new "Audio Bin" window. You'll want to right click on your song, then select "Create New Event":

Choose "2D Event", hit Create, then close the Audio Bin window.

4. On the left panel, switch to the Events tab: you'll find your song there. Drag it into a directory with your nickname and rename it so that the name doesn't contain symbols / spaces / etc.

5. Assign your song/sound to your bank:

6. Re-route your new event to the right bus:

   • Open the mixer window.
     

   • Right-click your event and reroute the event to the mains group. Don't create a new group.
     

   • You can now close the mixer window.

7. Add the fade parameter to your music:

   • Add the shared fade parameter by clicking the (+) tab.
     

   • Add automation to the master volume in the fade parameter tab.
     

   • Add two points at the 2 edges of the graph: -∞ dB to 0.00 dB
     

   • You now have a "fade" cursor on top of the screen, adjusting now will control the music volume. This is what music fade triggers use to adjust the music volume as well.

8. Make your music loop:

   • Switch back to the Timeline tab, then right click the black logic track above your audio track, and select "Add Loop Region".

   • Extend the loop region to however you see fit.

   

9. Right-click your bank and press Build. When this is done, you will find your bank in fmodstudio20000celeste-project/FMOD Studio Celeste Project/Build/Desktop.

   • Take only the .bank file that has the name of the bank you created earlier, for example yournickname_mapname.bank (don't take Master Bank.bank and other ones, those are the vanilla banks) and copy it to your mod's folder, in Mods/yourmod/Audio.

10. Generate the GUIDs.txt:

Once generated, you'll find it in fmodstudio20000celeste-project/FMOD Studio Celeste Project/Build/GUIDs.txt. Copy it to your mod's folder, in Mods/yourmod/Audio and rename it to yourbankname.guids.txt:

11. In Ahorn, you can use your music by typing its event name manually. For example, if you have this in the Events tab:

You can use this in Ahorn:

Type the path manually, it does not appear in the dropdown. That's normal!

Custom Sounds

The procedure to add custom sounds is similar to this, but sounds need to be redirected to another bus and you can skip the "make it loop" and "add a fade parameter" steps. For gameplay sounds, use the gameplay_sfx/game/general/yes_pause bus.

Overwriting Vanilla Events

If you would like to overwrite vanilla music/sounds, e.g. for use in a global skinmod, go to the Events in the FMOD sidebar that you'd like to replace, delete the audio present in the Event and replace it with your own. Then, right click the Event, go to "Assign to Bank" and select the bank for your mod (see Step 2 of the above tutorial for creating new banks) - this step is highly important as it means you will not redistribute the entirety of the vanilla banks with your mod, which is probably violating some copyright laws and will save you from including well over 100mb of unnecessary data in your mod. Build the bank, export the GUIDs, add them to the Audio folder in your mod (Steps 9 and 10 above), and have fun.

⚠️ This process is only viable as of Everest version 3014, so be sure to set this as the minimum required version to install your mod in your everest.yaml. On versions below this, if two separate mods try to overwrite the same event, the game will crash.

If you're worried about losing the vanilla audio in your copy of the FMOD Project when you go to overwrite these Events, you can easily back them up to another folder by copy-pasting them. You can also always install a fresh copy of the FMOD Project from the FMOD downloads page if necessary.