Orrery Terrain · OrreryTerrain module · class

UOrreryTerrainSplineFeatureComponent

A terrain feature that follows a spline: a corridor along an open spline or a plate inside a closed one, owned by this component and replaced in place (same id, same stack position) by each Rebuild.

Declaration

UCLASS(ClassGroup=(Orrery), meta=(BlueprintSpawnableComponent, DisplayName="Terrain Spline Feature"))
class UOrreryTerrainSplineFeatureComponent : public UActorComponent

Header: #include "OrreryTerrainSplineFeatureComponent.h"
Module: PublicDependencyModuleNames.Add("OrreryTerrain"); in your module’s Build.cs.
Stability: Experimental: supported, may change in a minor version, with a changelog line.
Thread: Game thread.
Derives from: UActorComponent
Blueprint: “Terrain Spline Feature”, a Blueprint type

Description

Owner: the terrain editor's domain ('TSED') with OwnerKey, a random key with bit 63 set made when the component first registers in a world. The editor session, the authoring capture, the bake and the multiplayer checks treat it as any editor feature.
Link: by FeatureId with the owner checked, else by OwnerKey. Loading, streaming in and linking never commit: the terrain's save is the truth, and the spline only matters when Rebuild is called.
Runtime: nothing rebuilds or removes on its own. Call Rebuild (or the async node) when the game's edit ends; IsStale says when one is due. EndPlay leaves the ground alone.
Multiplayer: FeatureId replicates. A client never commits, never makes keys and never decides copies; its async Rebuild asks the server to replace the feature, and the server's edit policy judges it.

Experimental in v1.0: the editor side leans on an experimental engine notification.

Note.

Game thread. Tier 3: no ground data lives here.

Functions

UOrreryTerrainSplineFeatureComponent
RebuildBlueprint
Commit the feature from the spline as it is now: replaces the linked feature in place (same id), or adds one.
EvaluateBlueprint
What a Rebuild would do now, with nothing changed: replaces the linked feature in the evaluation.
RemoveFeatureBlueprint
Remove the linked feature and clear the link (the state becomes Unlinked).
GetStateBlueprint
Where the feature stands against the terrain now.
GetFeatureIdBlueprint
The linked feature's id (by FeatureId, else by OwnerKey); FeatureId when the terrain holds neither.
IsStaleBlueprint
True when the state is Stale: the feature exists, but the spline and parameters as they are now do not build it (they changed since the last build, or another author, a client's request included, replaced the feature).
ResolveSpline
The spline the feature follows: Spline, or the first spline component on this actor; null without one.
OnRegister
OnUnregister
BeginPlay
GetLifetimeReplicatedProps
PostDuplicate
GetComponentInstanceData

Properties

Name	Type	Default	Meaning
`kSplineOwnerBit`	`uint64`	`uint64(1) << 63`	Bit 63 of every OwnerKey: a spline feature's owner id never equals the terrain editor tools' own id (1).
`Spline`BlueprintReadWrite	`FComponentReference`	—	The spline the feature follows. Empty: the first spline component on this actor.
`Kind`BlueprintReadWrite	`EOrreryTerrainSplineFeatureKind`	`EOrreryTerrainSplineFeatureKind::Corridor`	Corridor (an open spline) or Plate (a closed spline). The other kind is refused.
`Corridor`BlueprintReadWrite	`FOrreryTerrainCorridorBP`	—	The corridor's parameters. Points and the owner fields are ignored: the spline gives the points, the component the owner.
`Plate`BlueprintReadWrite	`FOrreryTerrainPlateBP`	—	The plate's parameters. Polygon is ignored: the closed spline gives the outline.
`OutlineSpacing`BlueprintReadWrite	`double`	`100.0`	Distance between the plate outline's vertices along the spline, cm; widened so the outline keeps to 2048 vertices.
`FeatureId`	`int64`	`0`	The feature this component built, 0 before. Saved and replicated; never edited by hand.
`OwnerKey`	`int64`	`0`	The owner id of the feature: random, bit 63 set, made at the first registration in a world. 0 on a template.
`BuiltKey`	`int64`	`0`	The key of the shape the ground holds: the spline's key (sampled points at 1 mm, parameters) at the last commit, or, after another author replaced the feature with a shape this spline does not build, the stored feature's content key. 0 before.
`BuiltSource`	`TSoftObjectPtr<UOrreryTerrainSourceAsset>`	—	The terrain's source at the last commit: a feature gone on another source was baked in.

Blueprint

EvaluateOrrery › Terrain › Experimental
Get Feature IdOrrery › Terrain › Experimental
Get StateOrrery › Terrain › Experimental
Is StaleOrrery › Terrain › Experimental
RebuildOrrery › Terrain › Experimental
Remove FeatureOrrery › Terrain › Experimental