Table of Contents

Replacing image files

Images in OMORI contain most visual elements you can see through the game, those include but are not limited to:

Changing images can be done with any image editor and requires a decrypted copy of OMORI.

Finding the files to replace

The first step to modifying the game's images are locating the images you want to change. Images can be found under img in the folder of your decrypted copy.

Under img you should find the following folders

Each folder contains a series of image files, usually in a png format, that each serve the purpose indicated by the folder's name.

Folder nameFolder contents
animationsFrames that compose the animations appearing in combat
atlasesMiscellaneous images, themselves made out of images from other folders, mainly for ease of access and loading, editing those should not be required for anything
battlebacks1Backgrounds that appear in battle
charactersMiscellaneous sprites that appear in the overworld
enemiesImages of the enemies that appear in FOE FACTS
facesFaces of the various main characters, both in combat and out of combat
overlaysImages that appear overlaid on top of the game during certain story segments
parallaxesBackgrounds that appear on certain maps, most notably in BLACKSPACE
picturesMiscellaneous images used for all sorts of purposes
slotmachineImages that appear in the slot machine minigame in the LAST RESORT
sv_actorsImages of the enemies that appear in combat, including emotion variations and animations
systemImages that form the game's user interface
tilesetsTilesets that are used in maps throughout the game

Editing sets of images

Some images you might find appear to contain multiple sprites, those can either be used as animation frames, indications of a state, or both.

img/sv_actors/!battle_bun_bunny.png is an example of such an image

Those images can be divided in multiple ways, depending on their purpose in the game, as such it is recommended to keep in mind the original layout while editing the image. The division does not care for the image's size, as it is done dynamically.

For instance, all battle sprites are divided in a 4×6 pattern, the image that is displayed in the battle changes alongside the horizontal axis to form an animation, and the status of the enemy dictates the vertical position of the image (Neutral, taking damage, defeated, sad, angry and happy).

Note: Certain enemies, notably enemies that can feel more emotions than just SAD, ANGRY and HAPPY will have more vertical sprites in their image

Putting the images in a mod

After editing your images, you must put them in your mod folder under the same path relative to your decrypted /www/, for instance, if you have edited the image in www_playtest_01234567/img/sv_actors/!battle_bun_bunny.png, you must put that image in www/mods/<yourmodID>/img/sv_actors/!battle_bun_bunny.png.

Afterwards, you must edit the file www/mods/<yourmodID>/mod.json to include the path to your modified image's folder in its assets, so in our example, your mod.json should look similar to this:

{
    "id": "yourmodID",
    "name": "Your mod's name",
    "description": "A longer description for your mod",
    "version": "1.0",
    "files": {
      "plugins": [],
      "text": [],
      "data": [],
      "maps": [],
      "assets": ["img/sv_actors/"],
      "exec": []
    }
  }
 

And done! Your modified file should now appear in game in the place that you replaced.

Image Deltas

Image deltas are a special type of file introduced in OneLoader V1.0.0. They provide a new way to edit images in your mods, by storing the difference between the original image and the new one. While this technique takes a bit of time to load when the game starts, image deltas can be stacked on top of each other allowing for greater compatibility between different asset changing mods.

It is often recommended to use image deltas instead of replacing images if you are only changing a small part of an image, for instance if you are adding an accessory or a detail to a face.

Generating an image delta

To generate an image delta, simply follow the following steps

  1. Visit the OLID generator

  1. Upload the original unmodified file as the Source file
  2. Upload the modified file as the Target file
  3. Press process

You will be given a .olid file. To verify if your file works, use the delta applier with the original unmodified file as the Source file

Applying an image delta

Putting an image delta in an OMORI mod is similar to replacing raw images, however it does take a few more steps

  1. Put your olid file anywhere in your mod folder and take note of its path
  2. Add the entry “do_olid” to the “_flags” array in your mod.json file. If you do not have that array, create it.
  3. Add an entry with the syntax {“patch”:“img/<folder>/<original image file>.png”, “with”:“<path/to/olid/file>.olid”} to the “image_deltas” array in your mod.json file. If you do not have that array, create it.

For instance, if you have modified the file img/sv_actors/!battle_bun_bunny.png and your .olid file is stored in /<yourmodID>/olid/!battle_bun_bunny.olid, your mod.json file should look similar to this:

{
    "id": "yourmodID",
    "name": "Your mod's name",
    "description": "A longer description for your mod",
    "version": "1.0",
    "_flags":[
      "do_olid"
      ]
    "files": {
      "plugins": [],
      "text": [],
      "data": [],
      "maps": [],
      "assets": [],
      "exec": [],
      "image_deltas": [
        {"patch":"img/sv_actors/!battle_bun_bunny.png", "with":"/<yourmodID>/olid/!battle_bun_bunny.olid"}
       ]
    }
  }
 

And done! Your modified file should now appear in game in the place that you replaced.