The PCG Biome Core and Sample Plugins are examples of how to use the PCG Framework with features like Attribute Set Tables, Feedback loops, Recursive Sub-graphs and Runtime Hierarchical Generation.
This quick start guide explains how to use the biome creation tool from scratch, followed by instructions on how to add new biomes and assets.
Requirements
This section covers the requirements and steps required to get the PCG Biome Core working in a world.
Enabling Plugins
The PCG Biome Core and PCG Biome Sample are two distinct plugins:
PCG Biome Core: A standalone plugin that contains only what is required for the biome creation tool to work. This plugin has a dependency on the PCG Framework and PCG Geometry Script Interop plugins.
PCG Biome Sample: A content example showcasing the biome creation tool, which can be enabled in any project. This plugin has a dependency on the PCG Biome Core plugin.
To enable the plugins, open the Plugins settings. Enable PCG Biome Core to access the tool, and enable the PCG Biome Sample to access the content example. For more information on enabling plugins, see Working with Plugins.
Resources
To access all the content related to both the PCG Biome Core and Sample plugins, the Show Engine Content and Show Plugin Content content browser settings must be enabled. Open the Settings menu in the Content Browser and click the checkbox next to both options.
Content Browser paths:
/All/EngineData/Plugins/PCGBiomeCore/All/EngineData/Plugins/PCGBiomeSample
Disk paths:
..\Engine\Plugins\Experimental\PCGBiomeCore\..\Engine\Plugins\Experimental\PCGBiomeSample\
PCG Biome Core Content
All the base blueprint classes are located in the following folder: /All/EngineData/Plugins/PCGBiomeCore/Blueprints
The BP_PCGBiomeCore is the main blueprint class. It is pre-configured with a PCG component that refers to the Biome Core PCG graph and holds a box collision component as its volume.
The Biome Core PCG graph located at the plugin's root is the source and main graph to execute all logic for the Biome Core to work. It contains multiple subgraphs with their own nested subgraphs. All of these separate subgraphs are stored under the Core folder.
The Biome Core graph is located at the following path: /Script/PCG.PCGGraph'/PCGBiomeCore/BiomeCore.BiomeCore'
The tool relies on multiple data assets made from pre-made classes with specific structures to generate content. These assets are BiomeDefinitions, BiomeAssets and BiomeGenerators. They are located in their respective folders and ../Setup sub-folders. The default assets of each type are also available for testing and debugging.
PCG Biome Sample Content
The BiomeSampleLevel world is located in the following folder: /All/EngineData/Plugins/PCGBiomeSample/Maps
The world contains the pre-configured BP_PCGBiomeCore, biome textures, volume, and spline actors. Use this as a starting point to learn how to set up the tool and understand it.
The sample contains multiple biomes, generators, and assets as well as custom structures and data assets classes that inherit from the base Biome Core classes. These assets are located in their respective BiomeSample folders and ../Setup sub-folders.
The PCG Biome Sample plugin contains additional data, including a BiomeMap texture, a tiled Flow, and a SunExposure texture2Darray, located in the Tiles folder. The Sample plugin also includes example PCG assemblies, meshes, and filter graph instances.
World Setup
To set up a world and start using the PCG Biome Core, follow these steps:
Create a new level or open an existing world. The PCG Biome Core works with both World Partitioned and non-partitioned levels.
Add a new Landscape and set the world scale through the Landscape Editor mode. If you are starting from the Open World template or any existing level with an existing landscape, this step is not required.
The presence of a landscape is optional when working with the PCG Biome Core.
Add or drag a BP_PCGBiomeCore actor into the level. The provided BP_PCGBiomeCore blueprint class is located in the following folder:
/Script/Engine.Blueprint'/PCGBiomeCore/Blueprints/BP_PCGBiomeCore.BP_PCGBiomeCore'Adjust the BP_PCGBiomeCore actor's Volume component scale to change the world coverage. The tool uses this volume to constrain its generation and output.
The next section explains how to place a Biome actor that generates and spawns assets in the Biome Core volume.
Biomes, Generators, and Assets Setup
After the original world setup is done and validated, you can create a new biome with its definition and assets.
To create a new biome, add or drag a new BP_PCGBiomeVolume or BP_PCGBiomeSpline actor into the world. The actor must be added within the Biome Core actor volume, and must be overlapping the landscape surface.
The blueprint classes are available in the following folders:
/Script/Engine.Blueprint'/PCGBiomeCore/Blueprints/BP_PCGBiomeVolume.BP_PCGBiomeVolume'/Script/Engine.Blueprint'/PCGBiomeCore/Blueprints/BP_PCGBiomeSpline.BP_PCGBiomeSpline'
Next, you need to create a set of data assets for the biome definition, generators, and assets. Data assets can be added from the Content Browser, from the right-click menu, or by duplicating existing assets of the same class.
In Unreal Engine 5.6 and later, biome actors support local biome assets and a local default biome definition that is saved in the actor directly. This removes the need for separate data assets for biome definitions and biome assets. Having separate assets is still supported, and can be used for sharing and maintenance when working with multiple levels or instances.
Set the Biome Definition
To set the Biome definition, open the BP_PCGBiomeVolume asset and set the BiomeName, BiomeColor, and BiomePriority properties. This sets the default definition for the biome.
Optionally, you can overwrite the default definition by creating a separate data asset, following these steps:
Add a data asset of class BiomeDefinitionTemplate to the project’s content folder.
Open the data asset and set the BiomeName, BiomeColor, and BiomePriority properties.
Open the BP_PCGBiomeVolume asset and set the Definition property to refer to the definition data asset you created in step 1. This overwrites the default definition of the volume asset.
The definition asset can be shared and re-used in multiple biome volumes, splines, and worlds.
For more information about biome definitions, see Biome Definition.
Create a Biome Generator
To create a biome generator, add a new data asset of class BiomeGeneratorTemplate in the project’s content folder, and set its GeneratorType, GeneratorPriority, and GeneratorGraph properties.
These properties define your generator. The generator asset can and should be shared and re-used in multiple assets, as it provides the initial point data from a linked GeneratorGraph on which to assign and spawn assets.
The GeneratorGraph is a PCG graph or PCG graph instance, which creates and outputs point data created by sampling the world through world ray hit or raycasts.
To set the GeneratorGraph property, create a new PCG graph using the TPL_BiomeCore_Generator template, or copy it from the following folder:
/Script/PCG.PCGGraph'/PCGBiomeCore/GraphTemplates/TPL_BiomeCore_Generator.TPL_BiomeCore_Generator'
For more information about Biome generators, see Biome Generator.
Create a Biome Asset
To create a Biome asset, open the BP_PCGBiomeVolume asset and add an entry to the Local Assets array property. Set the asset's Generator property, a mandatory reference to the biome generator data asset created above, and set the Mesh property, a reference to the visual to spawn.
Optionally, you can create and add a separate data asset, following these steps:
Add a new separate data asset of class BiomeAssetTemplate in the project’s content folder.
Open the data asset.
Add an entry to the Biome Assets array property and set its Generator and Mesh properties.
Open the BP_PCGBiomeVolume asset.
Refer to the data asset as a new entry to the Assets array property.
All local assets and assets references are combined together when generating the local biome.
In the data asset, the Biome Assets array is the collection of assets to process and spawn. Each entry contains multiple properties to configure. Assets sharing the same generator reference use the same point data to spawn on and will be distributed randomly onto the generated points according to their weight value. The biome assets can be shared and re-used easily across any biomes.
For more information about biome assets, see Biome Assets.
Biome Generation
After setting up a biome definition, biome generator, and biome asset, an automatic refresh occurs. A new biome is created by spawning the defined assets constrained within the BP_PCGBiomeVolume and the Biome Core volume.
You can now extend the biome with more generators and assets. Any number of biomes can be created using the same process and exist in the same world or across multiple worlds. See the BiomeSampleLevel in the PCGBiomeSample plugin for a complete setup.
For reference, in the following image, a biome volume actor has been configured with multiple assets referencing and sharing only 2 custom generators, one for trees and one for rocks.
In the following example, several biome spline actors with their respective assets and priorities are overlapping and fades out using a 64m blending range.
