Authoring a custom biome

APLM ships nine built-in biomes plus three fully customizable slots: BiomeCustom1, BiomeCustom2, BiomeCustom3. Use the custom slots when your project needs a surface the built-ins do not cover, such as volcanic rock, alien terrain, salt flats, or a stylised art-direction surface.

The custom biomes are first-class. They get the same weather hooks, the same season hooks, the same texture variation, and the same triplanar mapping as the built-ins.

Set it up

1. Build a Texture2DArray with your BaseColor, Normal, and ORD or ORH slices in APLM’s standard slice order. Full walkthrough in Creating your own Texture2DArray.
2. Open your Material Instance.
3. Find the BiomeCustom1T2DA (or 2, or 3) parameter and assign your new T2DA.
4. Tune the per-surface parameters in the same Material Instance category:
   • Color, Offset, Gain, Brightness, Contrast, Saturation
   • Near Tiling, Far Tiling, Fade Length, Fade Offset
   • Variation Scale, Variation Level (if texture variation is enabled)
   • Variance Low, Variance High, Variance Strength
   • Specular, Roughness, Normal Strength, Normal Flatness
5. Paint BiomeCustom1 (or 2, or 3) onto the landscape. The Auto layer also routes through your custom biome wherever the automatic logic chooses it.

The full per-surface parameter set is documented in the parameters reference.

Hook into seasons

The custom biomes are wired into MPC_Seasons like the built-ins. Each one exposes the same eight seasonal overrides (color, offset, gain, brightness, contrast, saturation, specular, roughness).

To author a seasonal cycle for a custom biome, follow the season Blueprint workflow and use BiomeCustom1Color, BiomeCustom1Offset, and so on as the parameter names you write into MPC_Seasons.

Hook into weather

Same pattern. The custom biome carries bEnableBiomeCustom1Weather plus the standard wave/ripple/puddle parameters. Toggle it on in the Material Instance and the layer reacts to whatever your weather system writes into MPC_Weathers.

Tip

If you only need one custom surface, do not waste the other two slots on near-duplicates. Use the spare slots for genuinely distinct surfaces (for example a different planet biome or a mid-game terrain swap), since each slot keeps an independent T2DA + parameter set.

Where to next

• Creating your own Texture2DArray: the texture build step in detail
• Driving seasons from Blueprint: wire the custom biome into the seasonal cycle
• Biomes reference: the built-in biomes for comparison