Sprite Atlases

Football Manager uses sprite atlases - single images containing multiple smaller sprites packed together. Understanding atlases helps you make more targeted replacements.

What is a Sprite Atlas?

A sprite atlas is a large image containing many smaller images (sprites) arranged in a grid or packed layout:

Benefits:

• Efficient memory usage
• Faster loading
• Batch rendering

For skinning:

• You may need to replace entire atlases
• Or target individual sprites within them

Viewing Atlases

Asset Catalogue

The Asset Catalogue shows sprites from FM’s atlases:

Each sprite shows:

• Sprite name
• Dimensions
• Source atlas
• Position within atlas

Bundle Viewer

1. Go to Bundle Viewer
2. Find relevant bundle (e.g. ui-iconsspriteatlases)
3. View files

Sprite Replacement

Option 2: Replace Individual Sprites

Target specific sprites by name:

{
  "my-star.png": "icon_star_gold",
  "my-arrow.png": "icon_arrow_up"
}

FM Skin Builder patches these into the atlas automatically.

Option 2: Replace Entire Atlas (Not Recommended)

Replace the whole atlas image:

{
  "ui_icons_atlas.png": "my-icons-atlas"
}

Requirements:

• Your image must match exact dimensions
• All sprites positioned correctly
• Most complex but most control

Finding Sprite Names

Search the Catalogue

1. Go to Asset Catalogue
2. Filter by “Sprites”
3. Search by visual appearance or name
4. Copy sprite names for mapping

Bundle Viewer

1. Go to Bundle Viewer
2. Find relevant bundle (e.g. ui-icons)
3. View files

Common Patterns

Creating Replacements

For Individual Sprites

Match the sprite’s dimensions exactly:

1. Find sprite dimensions
2. Create your image at that size
3. Map by sprite name

Example:

Sprite icon_star_gold is 32x32.

1. Create graphics/icons/my-star.png at 32x32
2. Map it:

{
  "my-star.png": "icon_star_gold"
}

Multi-Resolution Support

Some atlases have multiple resolutions:

ui_icons_atlas.png       (1x)
[email protected]    (2x)
[email protected]    (4x)

For best results:

• Provide matching resolution variants
• Use wildcards with 4x support to start with, the 2x and 1x will be generated automatically
• Or let FM scale (may reduce quality)

{
  "my-sprite_1x.png": "in-game-sprite_1x",
  "my-sprite_2x.png": "in-game-sprite_2x",
  "my-sprite_3x.png": "in-game-sprite_3x",
  "my-sprite_4x.png": "in-game-sprite_4x",
  /* OR wildcards*/
  "my-sprite.png": "in-game-sprite_*",
}

Tips and Best Practices

Match Exact Dimensions

Sprites must be exactly the right size:

• Too large → clipped
• Too small → stretched or misaligned

Maintain Transparency

For icons:

• Use PNG format
• Preserve alpha channel
• Match original transparency

Test Each Replacement

Replace one sprite at a time:

1. Map single sprite
2. Build
3. Verify it appears correctly
4. Continue with more

Use Wildcards Carefully

{
  "my-star.png": "my-star_*"  // Replaces ALL star sprites with same image
}

Good for consistent replacements, but may cause issues if sprites have different sizes.

Troubleshooting

”Sprite looks wrong”

• Dimensions don’t match original
• Position offset in atlas changed
• Transparency not preserved

”Sprite not appearing”

• Wrong sprite name (check catalogue)
• Mapping file in wrong folder
• Folder not in config includes

”Atlas looks corrupted”

When replacing entire atlas:

• Dimensions must match exactly
• All sprite positions must be preserved
• Format must be compatible

”Some sprites replaced, others not”

• Multiple atlases may contain similar sprites
• Try more specific sprite names
• Check which atlas each sprite belongs to

Next: Font Replacement - Add custom fonts.