初始提交: UE5.3项目基础框架

Plugins/CesiumForUnreal/Source/CesiumRuntime/Public/CesiumOriginShiftComponent.h

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+// Copyright 2020-2024 CesiumGS, Inc. and Contributors
+
+#pragma once
+
+#include "CesiumGlobeAnchoredActorComponent.h"
+#include "CoreMinimal.h"
+#include "CesiumOriginShiftComponent.generated.h"
+
+class UCesiumGlobeAnchorComponent;
+
+/**
+ * Indicates how to shift the origin as the Actor to which a
+ * CesiumOriginShiftComponent is attached moves.
+ */
+UENUM(BlueprintType)
+enum class ECesiumOriginShiftMode : uint8 {
+  /**
+   * This component is disabled and will have no effect.
+   */
+  Disabled,
+
+  /**
+   * The origin of the CesiumGeoreference will be changed when the Actor enters
+   * a new sub-level, but it will otherwise not be modified as the Actor moves.
+   * Any objects that are not anchored to the globe with a
+   * CesiumGlobeAnchorComponent will appear to move when the Actor enters a
+   * sub-level.
+   */
+  SwitchSubLevelsOnly,
+
+  /**
+   * The origin of the CesiumGeoreference will change as the Actor moves in
+   * order to maintain small, precise coordinate values near the Actor, as well
+   * as to keep the globe's local "up" direction aligned with the +Z axis. Any
+   * objects that are not anchored to the globe with a
+   * CesiumGlobeAnchorComponent will appear to move whenever the origin changes.
+   *
+   * When using this mode, all Cesium3DTileset instances as well as any Actors
+   * with a CesiumGlobeAnchorComponent need to be marked Movable, because these
+   * objects _will_ be moved when the origin is shifted.
+   */
+  ChangeCesiumGeoreference,
+};
+
+/**
+ * Automatically shifts the origin of the Unreal world coordinate system as the
+ * object to which this component is attached moves. This improves rendering
+ * precision by keeping coordinate values small, and can also help world
+ * building by keeping the globe's local up direction aligned with the +Z axis.
+ *
+ * This component is typically attached to a camera or Pawn. By default, it only
+ * shifts the origin when entering a new sub-level (a Level Instance Actor with
+ * a CesiumSubLevelComponent attached to it). By changing the Mode and Distance
+ * properties, it can also shift the origin continually when in between
+ * sub-levels (or when not using sub-levels at all).
+ *
+ * It is essential to add a CesiumGlobeAnchorComponent to all other non-globe
+ * aware objects in the level; otherwise, they will appear to move when the
+ * origin is shifted. It is not necessary to anchor objects that are in
+ * sub-levels, because the origin remains constant for the entire time that a
+ * sub-level is active.
+ */
+UCLASS(ClassGroup = "Cesium", Meta = (BlueprintSpawnableComponent))
+class CESIUMRUNTIME_API UCesiumOriginShiftComponent
+    : public UCesiumGlobeAnchoredActorComponent {
+  GENERATED_BODY()
+
+#pragma region Properties
+private:
+  /**
+   * Indicates how to shift the origin as the Actor to which this component is
+   * attached moves.
+   */
+  UPROPERTY(
+      EditAnywhere,
+      BlueprintReadWrite,
+      BlueprintGetter = GetMode,
+      BlueprintSetter = SetMode,
+      Category = "Cesium",
+      Meta = (AllowPrivateAccess))
+  ECesiumOriginShiftMode Mode = ECesiumOriginShiftMode::SwitchSubLevelsOnly;
+
+  /**
+   * The maximum distance between the origin of the Unreal coordinate system and
+   * the Actor to which this component is attached. When this distance is
+   * exceeded, the origin is shifted to bring it close to the Actor. This
+   * property is ignored if the Mode property is set to "Disabled" or "Switch
+   * Sub Levels Only".
+   *
+   * When the value of this property is 0.0, the origin is shifted continuously.
+   */
+  UPROPERTY(
+      EditAnywhere,
+      BlueprintReadWrite,
+      BlueprintGetter = GetDistance,
+      BlueprintSetter = SetDistance,
+      Category = "Cesium",
+      Meta = (AllowPrivateAccess))
+  double Distance = 0.0;
+#pragma endregion
+
+#pragma region Property Accessors
+public:
+  /**
+   * Gets a value indicating how to shift the origin as the Actor to which this
+   * component is attached moves.
+   */
+  UFUNCTION(BlueprintGetter)
+  ECesiumOriginShiftMode GetMode() const;
+
+  /**
+   * Sets a value indicating how to shift the origin as the Actor to which this
+   * component is attached moves.
+   */
+  UFUNCTION(BlueprintSetter)
+  void SetMode(ECesiumOriginShiftMode NewMode);
+
+  /**
+   * Gets the maximum distance between the origin of the Unreal coordinate
+   * system and the Actor to which this component is attached. When this
+   * distance is exceeded, the origin is shifted to bring it close to the Actor.
+   * This property is ignored if the Mode property is set to "Disabled" or
+   * "Switch Sub Levels Only".
+   *
+   * When the value of this property is 0.0, the origin is shifted continuously.
+   */
+  UFUNCTION(BlueprintGetter)
+  double GetDistance() const;
+
+  /**
+   * Sets the maximum distance between the origin of the Unreal coordinate
+   * system and the Actor to which this component is attached. When this
+   * distance is exceeded, the origin is shifted to bring it close to the Actor.
+   * This property is ignored if the Mode property is set to "Disabled" or
+   * "Switch Sub Levels Only".
+   *
+   * When the value of this property is 0.0, the origin is shifted continuously.
+   */
+  UFUNCTION(BlueprintSetter)
+  void SetDistance(double NewDistance);
+#pragma endregion
+
+public:
+  UCesiumOriginShiftComponent();
+
+protected:
+  virtual void TickComponent(
+      float DeltaTime,
+      ELevelTick TickType,
+      FActorComponentTickFunction* ThisTickFunction) override;
+};