Creating Custom Hytale Assets

Complete guide for creating and managing custom assets including models, textures, sounds, and particles.

When to use this skill

Use this skill when:

• Creating asset packs for plugins
• Adding custom textures and models
• Configuring sounds and music
• Creating particle effects
• Setting up animations
• Managing asset inheritance and tags

Asset System Architecture

Hytale uses a hierarchical asset system:

AssetPack
├── Server/          # Server-side assets
│   └── Content/     # Game content definitions
│       ├── BlockTypes/
│       ├── Items/
│       ├── Entities/
│       └── ...
└── Client/          # Client-side assets
    ├── Models/
    ├── Textures/
    ├── Sounds/
    ├── Particles/
    └── ...

Asset Pack Structure

my-plugin/
└── assets/
    ├── pack.json                    # Pack metadata
    ├── Server/
    │   └── Content/
    │       ├── BlockTypes/
    │       │   └── custom_block.blocktype
    │       ├── Items/
    │       │   └── custom_item.item
    │       ├── Entities/
    │       │   └── custom_entity.entity
    │       ├── Recipes/
    │       │   └── custom_recipe.recipe
    │       └── Sounds/
    │           └── custom_soundset.soundset
    └── Client/
        ├── Models/
        │   └── custom_model.model
        ├── Textures/
        │   ├── blocks/
        │   │   └── custom_block.png
        │   ├── items/
        │   │   └── custom_item.png
        │   └── entities/
        │       └── custom_entity.png
        ├── Sounds/
        │   └── custom/
        │       └── sound.ogg
        ├── Particles/
        │   └── custom_particle.particle
        └── Animations/
            └── custom_animation.animation

Pack Metadata

File: pack.json

{
  "Name": "MyPlugin Assets",
  "Id": "MyPlugin",
  "Version": "1.0.0",
  "Description": "Custom assets for MyPlugin",
  "Author": "Your Name",
  "Priority": 100,
  "Dependencies": ["Hytale:Core"]
}

Pack Properties

Property	Type	Description
Name	String	Display name
Id	String	Unique identifier
Version	String	Semantic version
Description	String	Pack description
Author	String	Creator name
Priority	Integer	Load order (higher = later)
Dependencies	Array	Required packs

Textures

Texture Formats

Format	Use Case
PNG	Standard textures (recommended)
TGA	Textures with alpha
DDS	Compressed textures

Block Textures

Location: Client/Textures/blocks/

custom_block.png          # All faces
custom_block_top.png      # Top face only
custom_block_side.png     # Side faces
custom_block_bottom.png   # Bottom face

Texture Size: 16x16, 32x32, 64x64 (power of 2)

Item Textures

Location: Client/Textures/items/

custom_item.png           # Inventory icon (32x32)
custom_item_held.png      # Held model texture

Entity Textures

Location: Client/Textures/entities/

custom_entity.png         # Main texture atlas
custom_entity_glow.png    # Emissive layer
custom_entity_normal.png  # Normal map

Models

Model Format

Hytale uses a custom JSON-based model format.

File: custom_model.model

{
  "Parent": "Hytale/Models/base_entity",
  "Textures": {
    "main": "MyPlugin/Textures/entities/custom_entity"
  },
  "Bones": [
    {
      "Name": "root",
      "Pivot": [0, 0, 0],
      "Children": [
        {
          "Name": "body",
          "Pivot": [0, 12, 0],
          "Cubes": [
            {
              "Origin": [-4, 0, -2],
              "Size": [8, 12, 4],
              "UV": [0, 0]
            }
          ],
          "Children": [
            {
              "Name": "head",
              "Pivot": [0, 24, 0],
              "Cubes": [
                {
                  "Origin": [-4, 0, -4],
                  "Size": [8, 8, 8],
                  "UV": [0, 16]
                }
              ]
            }
          ]
        }
      ]
    }
  ],
  "Animations": {
    "idle": "MyPlugin/Animations/custom_idle",
    "walk": "MyPlugin/Animations/custom_walk"
  }
}

Model Properties

Property	Type	Description
Parent	String	Parent model to inherit
Textures	Object	Texture bindings
Bones	Array	Bone hierarchy
Animations	Object	Animation bindings
Scale	Float	Overall scale
TextureSize	Array	Texture dimensions [W, H]

Bone Properties

Property	Type	Description
Name	String	Bone identifier
Pivot	Array	Rotation pivot point
Rotation	Array	Default rotation [X, Y, Z]
Cubes	Array	Geometry cubes
Children	Array	Child bones
Mirror	Boolean	Mirror UV horizontally

Cube Properties

Property	Type	Description
Origin	Array	Position offset
Size	Array	Dimensions [W, H, D]
UV	Array	Texture UV offset [U, V]
Inflate	Float	Expand cube size
Mirror	Boolean	Mirror this cube

Animations

File: custom_animation.animation

{
  "Length": 1.0,
  "Loop": true,
  "Bones": {
    "body": {
      "Rotation": {
        "0.0": [0, 0, 0],
        "0.5": [5, 0, 0],
        "1.0": [0, 0, 0]
      }
    },
    "leftArm": {
      "Rotation": {
        "0.0": [0, 0, 0],
        "0.25": [-30, 0, 0],
        "0.5": [0, 0, 0],
        "0.75": [30, 0, 0],
        "1.0": [0, 0, 0]
      }
    },
    "rightArm": {
      "Rotation": {
        "0.0": [0, 0, 0],
        "0.25": [30, 0, 0],
        "0.5": [0, 0, 0],
        "0.75": [-30, 0, 0],
        "1.0": [0, 0, 0]
      }
    }
  }
}

Animation Properties

Property	Type	Description
Length	Float	Duration in seconds
Loop	Boolean	Loop animation
Bones	Object	Per-bone keyframes

Keyframe Channels

Channel	Type	Description
Rotation	Array	Rotation [X, Y, Z] degrees
Position	Array	Position offset [X, Y, Z]
Scale	Array	Scale [X, Y, Z]

Sounds

Sound Formats

Format	Use Case
OGG	Music, ambient (recommended)
WAV	Short sound effects

Sound Event

File: custom_sound.soundevent

{
  "Sounds": [
    {
      "Path": "MyPlugin/Sounds/custom/sound1",
      "Weight": 1.0
    },
    {
      "Path": "MyPlugin/Sounds/custom/sound2",
      "Weight": 0.5
    }
  ],
  "Volume": {
    "Min": 0.8,
    "Max": 1.0
  },
  "Pitch": {
    "Min": 0.9,
    "Max": 1.1
  },
  "Category": "Effects",
  "Subtitle": {
    "en-US": "Custom sound plays"
  }
}

Sound Set

File: custom_soundset.soundset

{
  "Sounds": {
    "break": "MyPlugin/SoundEvents/custom_break",
    "place": "MyPlugin/SoundEvents/custom_place",
    "step": "MyPlugin/SoundEvents/custom_step",
    "hit": "MyPlugin/SoundEvents/custom_hit"
  }
}

Block Sound Set

File: custom_blocksound.blocksound

{
  "Break": {
    "Sound": "MyPlugin/SoundEvents/metal_break",
    "Volume": 1.0,
    "Pitch": 1.0
  },
  "Place": {
    "Sound": "MyPlugin/SoundEvents/metal_place",
    "Volume": 1.0
  },
  "Step": {
    "Sound": "MyPlugin/SoundEvents/metal_step",
    "Volume": 0.5
  },
  "Fall": {
    "Sound": "MyPlugin/SoundEvents/metal_fall"
  }
}

Sound Categories

Category	Description
Master	All sounds
Music	Background music
Effects	Sound effects
Ambient	Environmental sounds
Voice	Voice/dialogue
UI	Interface sounds
Weather	Weather sounds

Particles

File: custom_particle.particle

{
  "Texture": "MyPlugin/Textures/particles/sparkle",
  "MaxParticles": 100,
  "EmissionRate": 10,
  "Lifetime": {
    "Min": 0.5,
    "Max": 1.5
  },
  "Size": {
    "Start": 0.2,
    "End": 0.0
  },
  "Color": {
    "Start": { "R": 1.0, "G": 0.8, "B": 0.2, "A": 1.0 },
    "End": { "R": 1.0, "G": 0.2, "B": 0.0, "A": 0.0 }
  },
  "Velocity": {
    "Min": [-0.5, 1.0, -0.5],
    "Max": [0.5, 2.0, 0.5]
  },
  "Gravity": -0.5,
  "Collision": false,
  "BlendMode": "Additive"
}

Particle Properties

Property	Type	Description
Texture	String	Particle texture
MaxParticles	Integer	Maximum active particles
EmissionRate	Float	Particles per second
Lifetime	Range	Particle lifespan
Size	Range/Gradient	Size over lifetime
Color	Color/Gradient	Color over lifetime
Velocity	Range	Initial velocity
Gravity	Float	Gravity effect
Collision	Boolean	Collide with blocks
BlendMode	Enum	Alpha, Additive, Multiply

Block Particle

File: custom_blockparticle.blockparticle

{
  "Break": {
    "Particle": "MyPlugin/Particles/shatter",
    "Count": 30
  },
  "Step": {
    "Particle": "MyPlugin/Particles/dust",
    "Count": 3
  },
  "Ambient": {
    "Particle": "MyPlugin/Particles/glow",
    "Rate": 1,
    "Radius": 0.5
  }
}

Trails

File: custom_trail.trail

{
  "Texture": "MyPlugin/Textures/trails/slash",
  "Width": 0.5,
  "Length": 10,
  "Lifetime": 0.3,
  "Color": {
    "Start": { "R": 1.0, "G": 1.0, "B": 1.0, "A": 1.0 },
    "End": { "R": 1.0, "G": 1.0, "B": 1.0, "A": 0.0 }
  },
  "BlendMode": "Additive",
  "AttachPoint": "weapon_tip"
}

Asset Inheritance

Assets can inherit from parents:

{
  "Parent": "Hytale:Stone",
  "DisplayName": { "en-US": "Enchanted Stone" },
  "LightLevel": 5
}

Inheritance Rules

1. Child inherits all parent properties
2. Child can override any property
3. Nested objects merge (not replace)
4. Arrays replace (not merge)

Asset Tags

Categorize assets with tags:

{
  "Tags": {
    "Category": ["Building", "Decorative"],
    "Material": ["Stone"],
    "Origin": ["Natural", "Cave"]
  }
}

Tag Queries

Used in spawning, loot tables, etc.:

{
  "Blocks": {
    "MatchAll": ["Material:Stone"],
    "MatchAny": ["Category:Natural", "Origin:Cave"],
    "Exclude": ["Category:Artificial"]
  }
}

Localization

File: lang/en-US.json

{
  "item.myPlugin.customItem.name": "Custom Item",
  "item.myPlugin.customItem.description": "A special custom item",
  "block.myPlugin.customBlock.name": "Custom Block",
  "entity.myPlugin.customEntity.name": "Custom Creature"
}

Localization Keys

Pattern	Example
item.{plugin}.{id}.name	item.myPlugin.sword.name
block.{plugin}.{id}.name	block.myPlugin.ore.name
entity.{plugin}.{id}.name	entity.myPlugin.mob.name
ui.{plugin}.{key}	ui.myPlugin.menuTitle

Registering Assets in Plugin

@Override
protected void setup() {
    // Asset pack is auto-registered if manifest.json has:
    // "IncludesAssetPack": true
    
    // Listen for asset loading
    getEventRegistry().register(
        LoadedAssetsEvent.class,
        BlockType.class,
        this::onBlockTypesLoaded
    );
    
    getEventRegistry().register(
        LoadedAssetsEvent.class,
        Item.class,
        this::onItemsLoaded
    );
}

private void onBlockTypesLoaded(LoadedAssetsEvent<BlockType> event) {
    // Access loaded block types
    for (BlockType block : event.getLoadedAssets()) {
        getLogger().atInfo().log("Loaded block: %s", block.getId());
    }
}

Hot Reloading

Assets support hot-reload during development:

/reload assets

Listen for reload events:

getEventRegistry().register(
    AssetStoreMonitorEvent.class,
    this::onAssetReload
);

private void onAssetReload(AssetStoreMonitorEvent event) {
    if (event.getAssetStore().getAssetClass() == BlockType.class) {
        getLogger().atInfo().log("Block types reloaded");
        // Re-initialize dependent systems
    }
}

Custom Asset Store

Register entirely new asset types:

public class MyCustomAsset implements JsonAssetWithMap<String, DefaultAssetMap<String, MyCustomAsset>> {
    public static final AssetBuilderCodec<String, MyCustomAsset> CODEC = 
        AssetBuilderCodec.builder(MyCustomAsset.class, "MyCustomAsset")
            .appendRequired(Codec.STRING.fieldOf("Name"), MyCustomAsset::getName, (a, v) -> a.name = v)
            .appendOptional(Codec.INT.fieldOf("Value"), MyCustomAsset::getValue, (a, v) -> a.value = v, 0)
            .build();
    
    private String id;
    private String name;
    private int value;
    
    @Override
    public String getId() { return id; }
    public String getName() { return name; }
    public int getValue() { return value; }
}

// Register in plugin
@Override
protected void setup() {
    HytaleAssetStore<String, MyCustomAsset, DefaultAssetMap<String, MyCustomAsset>> store = 
        new HytaleAssetStore<>(
            MyCustomAsset.class,
            "MyCustomAssets",      // Directory name
            ".mycustomasset",      // File extension
            MyCustomAsset.CODEC,
            DefaultAssetMap::new
        );
    
    getAssetRegistry().register(store);
}

Troubleshooting

Textures Not Loading

1. Check file path matches reference
2. Verify PNG format and dimensions
3. Ensure pack.json is valid
4. Check console for loading errors

Models Not Displaying

1. Verify model JSON syntax
2. Check texture references exist
3. Ensure bone hierarchy is valid
4. Test with simpler model first

Sounds Not Playing

1. Check OGG/WAV format compatibility
2. Verify sound event references
3. Check volume and category settings
4. Ensure sound files exist at path

Asset Inheritance Not Working

1. Verify Parent path is correct
2. Check parent asset loads first
3. Ensure pack dependencies are set

See references/asset-formats.md for detailed format specs. See references/texture-specs.md for texture requirements.