GTNHLib/models.md

Model API

🌐 Languages: English | Українська

In general, it is designed to mimic the latest version.

Intentional deviations

None (for now).

Former deviations

Texture references are no longer assumed to be the same as 7.10 locations. Instead, they are resolved from assets/namespace/textures like modern does. This also means you can now use any texture in your ISBRH, and GTNHLib will inject it into the block atlas. Please use this power responsibly.

Resource packs can now replace most blocks, similarly to modern. Note that this primarily works on blocks with ISBRHS - if the block has a TESR registered in code, that should result in both the model and the TESR rendering.

Examples

BlockColor

Use to color to TintIndex

Example: using BlockColor register

BlockColor.registerBlockColors(new IBlockColor() {

    @Override
    public int colorMultiplier(IBlockAccess world, int x, int y, int z, int tintIndex) {
        // Return red for main layer, green for secondary
        return tintIndex == 0 ? 0xFF0000 : 0x00FF00;
    }

    @Override
    public int colorMultiplier(ItemStack stack, int tintIndex) {
        // Return blue for main layer, yellow for secondary
        return tintIndex == 0 ? 0x0000FF : 0xFFFF00;
    }
}, ModBlocks.MY_CUSTOM_BLOCK);

Example: implement IBlockColor directly in a block

public class BlockTestTint extends Block implements IBlockColor {

   public BlockTestTint() {
       super(Material.wood);
   }

   @Override
   public int colorMultiplier(IBlockAccess world, int x, int y, int z, int tintIndex) {
       return switch(tintIndex) {
           case 0 -> 0xFF0000; // red
           case 1 -> 0x00FF00; // green
           case 2 -> 0x0000FF; // blue
           case 3 -> 0xFFFF00; // yellow
           case 4 -> 0xFF00FF; // magenta
           case 5 -> 0x00FFFF; // cyan
           default -> 0xFFFFFF; // white
       };
   }

   @Override
   public int colorMultiplier(ItemStack stack, int tintIndex) {
       return colorMultiplier(null, 0, 0, 0, tintIndex);
   }
}

BlockState Api

Instead of relying on 4-bit metadata, model selection can resolved from full block state data via registered BlockProperty.

This allows:

• Unlimited logical states (no 16-meta restriction)
• Model variants based on TileEntity data
• ItemStack-aware state resolution
• Dynamic rendering behavior

BlockState resolution works in three steps:

1. A BlockProperty is registered to a block (and optionally its item).
2. The property provides values from:
   • World + TileEntity
   • ItemStack
3. The JsonModel loader resolves model variants using those property values.

1.Creating a BlockProperty

Example: Direction property backed by TileEntity.

DirectionBlockProperty property = new DirectionBlockProperty() {

    @Override
    public String getName() {
        return "facing";
    }

    @Override
    public boolean hasTrait(BlockPropertyTrait trait) {
        return switch (trait) {
            case SupportsWorld, WorldMutable, StackMutable, SupportsStacks -> true;
            default -> false;
        };
    }

    @Override
    public ForgeDirection getValue(IBlockAccess world, int x, int y, int z) {
        TileEntity te = world.getTileEntity(x, y, z);
        if (te instanceof TileTestTintMul tile) {
            return tile.getFacing();
        }
        return ForgeDirection.NORTH;
    }

    @Override
    public void setValue(World world, int x, int y, int z, ForgeDirection value) {
        TileEntity te = world.getTileEntity(x, y, z);
        if (te instanceof TileTestTintMul tile) {
            tile.setFacing(value);
        }
    }

    @Override
    public ForgeDirection getValue(ItemStack stack) {
        return ForgeDirection.NORTH;
    }
};

2.Registering the Property

BlockPropertyRegistry.registerProperty(block, property);
BlockPropertyRegistry.registerProperty(Item.getItemFromBlock(block), property);

You must register:

• On the block (world state)
• On the item (inventory rendering)

3.Defining blockstate JSON

Example:

{
  "variants": {
    "facing=north": { "model": "modid:block/machine_north" },
    "facing=south": { "model": "modid:block/machine_south" },
    "facing=west":  { "model": "modid:block/machine_west" },
    "facing=east":  { "model": "modid:block/machine_east" }
  }
}

The loader will:

• Query property.getValue(...)
• Build a state string like: facing=north
• Resolve the correct model variant

Supported Traits

BlockPropertyTrait controls where the property works:

• SupportsWorld → usable in world rendering
• SupportsStacks → usable in item rendering
• WorldMutable → value can be changed in world
• StackMutable → value can be changed in ItemStack

Only implement the traits you need.

TODO

• Add smooth shading to ModelISBRH.
• Add face culling to models.
• Implement UV locking.