Every editable field of the Agentic Biome data asset (UAgenticBiome) and the structs, enums and generator asset it nests, with types, defaults and backend notes

Biome Asset Reference

UAgenticBiome (shown in Unreal as Agentic Biome) is a UPrimaryDataAsset with primary asset type AgenticBiome. One asset holds a biome's identity, its offline species rows, its runtime ground-cover entries and its landscape layer. This page lists every editable property, one table per struct. For the workflow, see Biome Assets.

Labels and names. The Details panel shows each C++ name with spaces inserted and the b prefix of a boolean dropped (bSolo shows as Solo). Tables give the C++ name. The eighteen BiomeCore fields of a species row use BiomeCore's own names and spellings, carried verbatim, including SelfPrunIngExtentsMultiplier and the enumerator that shows as Additiive. Descriptions of BiomeCore-defined fields follow BiomeCore's own field descriptions. Advanced in a table marks a field the plugin flags as advanced, one you rarely need to change.

Metadata only. DisplayName and Description are labels for people. DisplayName appears in the Output Log lines of sector builds, and nothing reads Description. Neither changes placement, ground cover or any other behaviour of the biome.

Agentic Biome (`UAgenticBiome`)

The Details panel orders the categories: Validation (a live issue list, see Biome Assets), Identity, Species, Ground cover, Landscape, Provenance.

Identity

Property	Type	Default	Meaning
`DisplayName`	`FText`	empty	Human-readable label. Metadata only: it appears in the Output Log lines of sector builds and nothing else reads it.
`Description`	`FText` (multi-line)	empty	Free-text note for the people who open the asset, shown as metadata. Nothing reads it.
`Definition`	`FAgenticBiomeDefinition`	see Definition	Name, map colour and priority. Copied onto each region built from this biome as its default definition. It is the only place the biome's colour lives.

Species

Property	Type	Default	Meaning
`Species`	`TArray<FAgenticSpeciesRow>`	empty	Offline (placed) species: trees, rocks, shrubs and props. Written inline onto each region's `LocalAssets`. Each element is one species row; the array element title is the row's `SpeciesId`.

Ground cover

Property	Type	Default	Meaning
`RuntimeAssetEntries`	`TArray<FAgenticRuntimeAssetEntry>`	empty	The list of GPU runtime ground-cover templates (`RT_*`) the biome uses, each with a per-backend mask. This is the list a build reads. Element title is `Asset`. See Runtime asset entry.
`RuntimeAssets`	`TArray<TSoftObjectPtr<UObject>>`	empty	Legacy list, shown under Advanced. A build never reads it. When the asset loads with `RuntimeAssetEntries` empty, every non-empty element here is moved into `RuntimeAssetEntries` with both backends ticked, and this array is cleared. Use `RuntimeAssetEntries`.

Landscape

Property	Type	Default	Meaning
`LandscapeLayerName`	`FName`	`None`	Name of the Landscape paint layer this biome follows. Used where masks are baked from Landscape weightmaps and by the paint-to-biome-map tool. Read from Landscape weightmaps only: on MeshTerrain the weight layers cannot be read by this path. A biome with `None` here is skipped by those paths.

Provenance

Property	Type	Default	Meaning
`Revision`	`int32`	`0`	Read-only in Details. Increases by one on every property edit of the asset, including edits to `Description`. A region stores the value it was built from as `SpawnedFromRevision`. It is a label, not the staleness test: a region is stale when the hash of the rows the biome emits, or of its runtime entries, differs from the hash stored when the region was built.

Definition (`FAgenticBiomeDefinition`)

Property	Type	Default	Meaning
`BiomeName`	`FName`	`None`	The biome's identity. The Terraformer's palette check warns when two palette biomes share a name.
`BiomeColor`	`FLinearColor`	white (1, 1, 1)	The colour this biome claims in a biome map. Alpha is hidden and not used. It must not be black, which a map reads as "no biome", and it must differ from every other palette colour by more than the Terraformer's `Biome Color Tolerance` (default `0.01`) in at least one of R, G or B.
`BiomePriority`	`int32`	`0`	Higher wins where two biomes claim the same ground. Note the opposite polarity of a generator's `GeneratorPriority`.

Runtime asset entry (`FAgenticRuntimeAssetEntry`)

Property	Type	Default	Meaning
`Asset`	`TSoftObjectPtr<UObject>`	none	A runtime ground-cover template (an `RT_*` asset). A template that fails to load is skipped with a warning in the log.
`Backends`	`int32` bitmask	`3` (both)	Which terrain backends use this entry. The Details checkboxes are Landscape (value `1`) and Mesh Terrain (value `2`). With neither ticked the entry is never carried to a region.

Species row (`FAgenticSpeciesRow`)

A row has four fields of its own plus the eighteen BiomeCore fields of its base struct. Only the BiomeCore fields reach BiomeCore; the four authoring fields stay on the biome asset.

The Details panel gives each row a header: the Enabled checkbox, the SpeciesId (or the mesh name when the id is empty), the mesh, the weight, the generator with its sub-type, a backend readout such as [L|M], and SOLO or ISO when set. The body is grouped as Placement, Filters, Mesh rendering, Backends, Runtime scatter, Children & assemblies, and Debug. Enabled appears only in the header.

Authoring fields

Property	Type	Default	Meaning
`SpeciesId`	`FName`	`None`	Stable key for the row. Tools address a row by it, and an upsert replaces the row with the same id. Required, and unique within the biome.
`bSolo`	`bool`	`false`	Authoring solo. When any enabled row in the biome has it set, only soloed enabled rows are emitted. Details label: "Solo (authoring) - only soloed rows are emitted". A soloed row that is itself disabled does not trigger solo mode.
`Backends`	`int32` bitmask	`3` (both)	Which terrain backends this row serves: Landscape (`1`), Mesh Terrain (`2`). A row that excludes the resolved backend is not emitted. With neither ticked the row is never emitted.
`BackendOverrides`	`TMap<EAgenticTerrainBackend, FAgenticBackendOverride>`	empty	Sparse per-backend replacement of `Generator` and `ChildAssets`. Advanced. See Backend override.

BiomeCore fields

Property	Type	Default	Meaning
`Enabled`	`bool`	`true`	Whether the row is used. An unticked row is dropped before BiomeCore sees it.
`AssetType`	`FName`	`None`	Label identifying the asset type. Shipped rows use `Tree`, `Rock` and `Clutter`. Advanced.
`Weight`	`double`	`1.0`	Distribution weight among the rows that share a generator. Minimum `0`. A weight of `0` or less is a validator error.
`Generator`	`TSoftObjectPtr<UObject>`	none	The generator asset whose points this species is placed on. The picker accepts an Agentic Biome Generator asset or a BiomeCore generator Blueprint asset. Required.
`GeneratorSubType`	`FName`	`None`	Restricts the species to a subset of the generator's points. A comma-separated list is accepted, which lets one generator serve several species. Sub-types are defined in the generator's graph.
`TransformGraph`	`TSoftObjectPtr<UPCGGraphInterface>`	none	Optional PCG graph that modifies or produces points, for example to scatter secondary points around a tree. When unset, the incoming point is used as is. Advanced.
`Mesh`	`TSoftObjectPtr<UStaticMesh>`	none	Static mesh spawned into an instanced mesh component.
`SkeletalMesh`	`TSoftObjectPtr<USkeletalMesh>`	none	Skeletal mesh to spawn. Advanced.
`Assembly`	`TSoftObjectPtr<UObject>`	none	PCG Data Asset assembly to spawn. Advanced.
`Actor`	`FSoftClassPath`	none	Actor class to spawn. Class picker limited to `Actor`. Advanced.
`ChildAssets`	`TSoftObjectPtr<UObject>`	none	A BiomeCore biome-asset Blueprint asset (the shipped `Child_*` assets) that spawns further assets on this row's points, recursively.
`DebugOptions`	`FAgenticBiomeDebugOptions`	see below	BiomeCore render isolation. Details label: "BiomeCore render isolation - does not change what is emitted".
`AssetOptions`	`FAgenticBiomeAssetOptions`	see below	Per-instance transform and pruning policy.
`MeshOptionsPreset`	`TSoftObjectPtr<UObject>`	none	A BiomeCore mesh-options preset Blueprint asset. When set, it replaces all of `MeshOptions`, and Details hides `MeshOptions` and shows "MeshOptions is not read: preset '...' replaces all 20 values." Advanced.
`MeshOptions`	`FAgenticBiomeMeshOptions`	see below	Settings forwarded onto the spawned instanced mesh component. Ignored when `MeshOptionsPreset` is set.
`AssemblyOptions`	`FAgenticBiomeAssemblyOptions`	see below	Options for assembly spawns. Advanced.
`FilterOptions`	`FAgenticBiomeFilterOptions`	see below	Culls generated points before the asset is placed on them.
`RuntimeOptions`	`FAgenticBiomeRuntimeOptions`	see below	Options for BiomeCore's runtime generation. Advanced.

A row with Mesh, SkeletalMesh, Assembly and Actor all empty has nothing to spawn. The SetSpecies tool refuses such a row ("Row spawns nothing"); the validator does not check for it, and the shipped Tree and Tree_MT rows are examples.

Backend override (`FAgenticBackendOverride`)

Both fields are optional. An unset field means "use the row's own value". A set field replaces the row's value for that backend and outranks it.

Property	Type	Default	Meaning
`Generator`	`TSoftObjectPtr<UObject>`	none	Generator used instead of the row's `Generator` on this backend.
`ChildAssets`	`TSoftObjectPtr<UObject>`	none	Child asset used instead of the row's `ChildAssets` on this backend.

The map key is EAgenticTerrainBackend. A build looks up only the Landscape and MeshTerrain keys.

Shown in the row's Filters group. The first four fields are BiomeCore's own; the other six are sample-tier fields.

Property	Type	Default	Meaning
`DensityMin`	`double`	`0.0`	Reject points whose density is below this. Range `0` to `1`.
`DensityMax`	`double`	`1.0`	Reject points whose density is above this. Range `0` to `1`.
`HeightMin`	`double` (cm)	`-100000.0`	World-Z floor in centimetres.
`HeightMax`	`double` (cm)	`100000.0`	World-Z ceiling in centimetres.
`FlowMin`	`double`	`0.0`	Reject points whose flow (drainage accumulation) is below this. Range `0` to `1`. Landscape only.
`FlowMax`	`double`	`1.0`	Reject points whose flow is above this. Range `0` to `1`. Landscape only.
`SunExposureMin`	`double`	`0.0`	Reject points whose sun exposure is below this. Range `0` to `1`. Landscape only.
`SunExposureMax`	`double`	`1.0`	Reject points whose sun exposure is above this. Range `0` to `1`. Landscape only.
`WaterDistanceMin`	`double` (cm)	`0.0`	Reject points closer to water than this. No water-distance producer ships, so it does not change placement.
`WaterDistanceMax`	`double` (cm)	`100000.0`	Reject points further from water than this. No water-distance producer ships, so it does not change placement.

Backend notes for the six sample-tier fields:

On Landscape, flow and sun exposure are read from two textures that ship with the plugin (T_AT_Flow_Terraformer and T_AT_SunExposure_Terraformer), installed through the filter chain AT_Filters_Inst. They were baked for the terrain of the showcase levels.
On MeshTerrain there is no flow or sun-exposure source. The validator reports SampleFilterOnMeshTerrain for any of the six fields set away from its default on a row that serves MeshTerrain.
The filter chain installs no water-distance filter, so WaterDistanceMin and WaterDistanceMax have no effect on either backend. The validator still checks them on MeshTerrain rows.

Asset options (`FAgenticBiomeAssetOptions`)

Shown in the row's Placement group.

Property	Type	Default	Meaning
`OverlapWithChildren`	`bool`	`false`	Allow overlapping with child assets. Advanced.
`ForceAssetScale`	`bool`	`false`	Ignore the scale set by the transform graph. Advanced.
`ExtentsMultiplier`	`FVector`	(1, 1, 1)	Scales the asset's bounds. Advanced.
`BoundsOffset`	`FVector` (cm)	(0, 0, 0)	Offset applied to the bounds computed from the asset. Advanced.
`Translation`	`FVector`	(0, 0, 0)	Position offset applied over the generator point's position.
`Rotation`	`FRotator`	(0, 0, 0)	Rotation offset applied over the generator point's rotation.
`Scale`	`FVector`	(1, 1, 1)	Scale factor applied over the generator point's scale.
`OrientUpward`	`double`	`0.0`	Range `0` to `1`. `0` keeps the surface normal, `1` forces world up; values between blend from the generator point's normal to world Z up.
`SelfPrune`	`bool`	`false`	Remove overlapping points of this asset. The checkbox sits inline with the next field.
`SelfPrunIngExtentsMultiplier`	`double`	`1.0`	Scale applied to extents to change self-pruning behaviour. Shown only while `SelfPrune` is on. The capital `I` in the name is BiomeCore's spelling and is the real property name.

Mesh options (`FAgenticBiomeMeshOptions`)

Shown in the row's Mesh rendering group. Forwarded onto the spawned instanced mesh component. Ignored entirely when the row sets MeshOptionsPreset.

Property	Type	Default	Meaning
`Material`	`TSoftObjectPtr<UMaterialInterface>`	none	Material override for the mesh. Advanced.
`AllowCollision`	`bool`	`false`	BiomeCore describes it as "Use Default Mesh Collision settings".
`Visible`	`bool`	`true`	Whether the mesh component is visible. Advanced.
`CastShadow`	`bool`	`true`	Whether the mesh casts shadows.
`CastHiddenShadow`	`bool`	`false`	Whether the mesh casts shadows when hidden. Advanced.
`CastDynamicShadow`	`bool`	`true`	Whether the mesh casts shadows in the case of non-precomputed shadowing. Advanced.
`AffectDistanceFieldLighting`	`bool`	`true`	Whether the mesh affects distance-field lighting methods. Only used when `CastShadow` is true. Advanced.
`AffectDynamicIndirectLighting`	`bool`	`true`	Whether the mesh influences indirect lighting. Advanced.
`VisibleInRayTracing`	`bool`	`true`	Whether the mesh is visible in ray-traced reflections and shadows. Advanced.
`DetailMode`	`int32`	`0`	Required detail level of the mesh. Advanced.
`StartCullDistance`	`double` (cm)	`0.0`	Distance from the camera at which each instance starts to fade out.
`EndCullDistance`	`double` (cm)	`0.0`	Distance from the camera at which each instance has completely faded out.
`EvaluateWorldPositionOffset`	`bool`	`true`	Whether to evaluate world position offset. The checkbox sits inline with the next field. Advanced.
`WorldPositionOffsetDisableDistance`	`double` (cm)	`0.0`	Distance at which world position offset is disabled for an instance. `0` means never disable. Editable only while `EvaluateWorldPositionOffset` is on. Advanced.
`IncludeInHLOD`	`bool`	`false`	Include the mesh in HLOD. The checkbox sits inline with the next field. Advanced.
`HLODLayer`	`TSoftObjectPtr<UHLODLayer>`	none	HLOD layer the mesh is assigned to. Shown only while `IncludeInHLOD` is on. Advanced.
`CanEverAffectNavigation`	`bool`	`true`	Whether the mesh can influence navigation. Advanced.
`RasterizeAsFilledConvexVolume`	`bool`	`false`	Whether navigation geometry from the mesh is converted into a filled vertical convex volume. Advanced.
`IsSpatiallyLoaded`	`bool`	`true`	Whether the mesh is spawned on an actor that is spatially loaded in a partitioned world. Advanced.
`ComponentTags`	`FString`	empty	Comma-separated values applied as additional component tags. A single string, not an array. Advanced.

Runtime options (`FAgenticBiomeRuntimeOptions`)

Shown in the row's Runtime scatter group; the struct is Advanced on the row. These are BiomeCore's runtime-generation options for a root row. The Details panel notes that they are inert on an offline row and that the runtime tier is fed by the biome's RuntimeAssetEntries list. An enabled row whose GenerationMethod is not None still makes the biome count as having runtime cover (for the validator's EmptyBiome check and the Terraformer's palette check).

Property	Type	Default	Meaning
`GenerationMethod`	`EAgenticGenerationMethod`	`None`	`None`, `AutoResolveRuntimeAssembly`, `RuntimeAssembly` or `OutputPoints`. The names are BiomeCore's. The shipped biomes use `RuntimeAssembly` together with a `RuntimeAssembly` asset.
`RuntimeAssembly`	`TSoftObjectPtr<UObject>`	none	The assembly used by runtime generation. The shipped biomes point at the `L_*MicroScattering_PCG` assets under `Sample/PCGAssemblies`.
`MeshSamplingRadius`	`double`	`5.0`	Asset mesh sampling parameter for runtime generation.
`InheritAssetScale`	`bool`	`false`	Inherit the asset's scale. BiomeCore gives no further description.
`ScaleMultiplier`	`double`	`1.0`	Scales the sampled mesh points.
`NormalOffset`	`double`	`1.0`	BiomeCore describes it as removing sampled mesh points based on normals.
`ZMin`	`double` (cm)	`0.0`	Removes sampled mesh points based on height.
`ZMax`	`double` (cm)	`500.0`	Removes sampled mesh points based on height.
`InfluenceType`	`EAgenticInfluenceType`	`None`	Asset influence behaviour at runtime: `None`, `Additive` (shown as `Additiive`, BiomeCore's spelling) or `Subtractive`.
`InfluenceRadius`	`double` (cm)	`100.0`	Asset influence radius at runtime.
`Tags`	`FString`	empty	Comma-separated tags. A single string, not an array.

Debug options (`FAgenticBiomeDebugOptions`)

Property	Type	Default	Meaning
`Isolate`	`bool`	`false`	Render only this row, hiding every other species in the biome. This is BiomeCore's per-row isolation and does not change which rows are emitted. For authoring, use the row's `bSolo`, which filters the list before BiomeCore sees it.
`ShowBounds`	`bool`	`false`	Display the asset's bounds for debugging. Advanced.

Assembly options (`FAgenticBiomeAssemblyOptions`)

Property	Type	Default	Meaning
`AllowCollision`	`bool`	`false`	Whether collisions are allowed or forced off on all assembly inner points.

Generator asset (`UAgenticBiomeGenerator`)

An Agentic Biome Generator is the asset a species row's Generator points at. It is a UPrimaryDataAsset with one property, Generator (FAgenticGeneratorDefinition), and it is read by BiomeCore the same way as BiomeCore's own generator Blueprint asset. The shipped generators are listed in Biome Assets.

Property	Type	Default	Meaning
`GeneratorType`	`FName`	`None`	Optional generator name. Shipped generators use it as a family label such as `Shared_Trees`.
`GeneratorGroups`	`FName`	`None`	Comma-separated list of groups that constrain priority-based difference between generators.
`GeneratorPriority`	`int32`	`0`	Priority over other generators. Smaller number means higher priority, the opposite of `BiomePriority`. BiomeCore's own authored range is `-1` to `1`; the validator reports a value outside it.
`GeneratorAllowOverlap`	`bool`	`false`	Bypass priority-based difference with overlapping points from other generators.
`GeneratorGraph`	`TSoftObjectPtr<UPCGGraphInterface>`	none	The PCG graph that generates all root points onto which the rows referencing this generator are assigned.
`GeneratorSpatialNoiseSettings`	`TSoftObjectPtr<UPCGSettingsInterface>`	none	Optional spatial noise that controls the weighted distribution of assets. Point it at a saved spatial-noise settings asset.

Enums

Enum	Values	Used by
`EAgenticBackendMask`	`Landscape` = 1, `MeshTerrain` = 2 (bit flags; `3` is both)	`Backends` on a species row and on a runtime asset entry
`EAgenticTerrainBackend`	`Auto`, `Landscape`, `MeshTerrain`	Key of `BackendOverrides`; the Terraformer's `Terrain Backend`
`EAgenticGenerationMethod`	`None`, `AutoResolveRuntimeAssembly`, `RuntimeAssembly`, `OutputPoints`	`GenerationMethod`
`EAgenticInfluenceType`	`None`, `Additive` (displayed `Additiive`), `Subtractive`	`InfluenceType`

Continue with the authoring guide, placement, or support.

Biome Asset Reference

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