Access to glTF tuner and tuned tiles versions in the Unreal plugin

CHANGES.md

@@ -5,6 +5,7 @@
 ##### Additions :tada:
 
 - Added support for `TRIANGLE_FAN` primitives in tile meshes.
+- Added an optional glTF model post-processing stage after the tile loading step, before the tile can be displayed.
 
 ##### Fixes :wrench:
 

Source/CesiumRuntime/Private/Cesium3DTileset.cpp

@@ -5,6 +5,7 @@
 #include "Camera/CameraTypes.h"
 #include "Camera/PlayerCameraManager.h"
 #include "Cesium3DTilesSelection/EllipsoidTilesetLoader.h"
+#include "Cesium3DTilesSelection/GltfModifier.h"
 #include "Cesium3DTilesSelection/Tile.h"
 #include "Cesium3DTilesSelection/TilesetLoadFailureDetails.h"
 #include "Cesium3DTilesSelection/TilesetOptions.h"
@@ -992,7 +993,10 @@ void ACesium3DTileset::LoadTileset() {
            ->EnableExperimentalOcclusionCullingFeature &&
        this->EnableOcclusionCulling && this->BoundingVolumePoolComponent)
           ? this->BoundingVolumePoolComponent->getPool()
-          : nullptr};
+          : nullptr,
+      {},
+      _gltfModifier
+  };
 
   this->_startTime = std::chrono::high_resolution_clock::now();
 
@@ -2325,3 +2329,8 @@ void ACesium3DTileset::RuntimeSettingsChanged(
   }
 }
 #endif
+
+void ACesium3DTileset::SetGltfModifier(
+    const std::shared_ptr<Cesium3DTilesSelection::GltfModifier>& InModifier) {
+  _gltfModifier = InModifier;
+}

Source/CesiumRuntime/Private/CesiumGltfComponent.cpp

@@ -3440,7 +3440,7 @@ UCesiumGltfComponent::CreateOffGameThread(
     UMaterialInterface* pBaseTranslucentMaterial,
     UMaterialInterface* pBaseWaterMaterial,
     FCustomDepthParameters CustomDepthParameters,
-    const Cesium3DTilesSelection::Tile& tile,
+    Cesium3DTilesSelection::Tile& tile,
     bool createNavCollision) {
   TRACE_CPUPROFILER_EVENT_SCOPE(Cesium::LoadModel)
 
@@ -3454,6 +3454,7 @@ UCesiumGltfComponent::CreateOffGameThread(
   // }
 
   UCesiumGltfComponent* Gltf = NewObject<UCesiumGltfComponent>(pTilesetActor);
+  Gltf->pTile = &tile;
   Gltf->SetMobility(pTilesetActor->GetRootComponent()->Mobility);
   Gltf->SetFlags(RF_Transient | RF_DuplicateTransient | RF_TextExportTransient);
 
@@ -3535,6 +3536,13 @@ UCesiumGltfComponent::UCesiumGltfComponent() : USceneComponent() {
   PrimaryComponentTick.bCanEverTick = false;
 }
 
+const CesiumGltf::Model* UCesiumGltfComponent::GetGltfModel() const {
+  if (pTile)
+    if (auto RenderContent = pTile->getContent().getRenderContent())
+      return &RenderContent->getModel();
+  return nullptr;
+}
+
 void UCesiumGltfComponent::UpdateTransformFromCesium(
     const glm::dmat4& cesiumToUnrealTransform) {
   for (USceneComponent* pSceneComponent : this->GetAttachChildren()) {

Source/CesiumRuntime/Private/CesiumGltfComponent.h

@@ -5,6 +5,7 @@
 #include "Cesium3DTilesSelection/Tile.h"
 #include "Cesium3DTileset.h"
 #include "CesiumEncodedMetadataUtility.h"
+#include "CesiumLoadedTile.h"
 #include "CesiumModelMetadata.h"
 #include "Components/PrimitiveComponent.h"
 #include "Components/SceneComponent.h"
@@ -56,7 +57,7 @@ struct FRasterOverlayTile {
 };
 
 UCLASS()
-class UCesiumGltfComponent : public USceneComponent {
+class UCesiumGltfComponent : public USceneComponent, public ICesiumLoadedTile {
   GENERATED_BODY()
 
 public:
@@ -87,7 +88,7 @@ class UCesiumGltfComponent : public USceneComponent {
       UMaterialInterface* BaseTranslucentMaterial,
       UMaterialInterface* BaseWaterMaterial,
       FCustomDepthParameters CustomDepthParameters,
-      const Cesium3DTilesSelection::Tile& tile,
+      Cesium3DTilesSelection::Tile& tile,
       bool createNavCollision);
 
   UCesiumGltfComponent();
@@ -104,6 +105,8 @@ class UCesiumGltfComponent : public USceneComponent {
   UPROPERTY(EditAnywhere, Category = "Rendering")
   FCustomDepthParameters CustomDepthParameters{};
 
+  Cesium3DTilesSelection::Tile* pTile = nullptr;
+
   FCesiumModelMetadata Metadata{};
   EncodedFeaturesMetadata::EncodedModelMetadata EncodedMetadata{};
 
@@ -132,6 +135,9 @@ class UCesiumGltfComponent : public USceneComponent {
 
   virtual void BeginDestroy() override;
 
+  // from ICesiumLoadedTile
+  const CesiumGltf::Model* GetGltfModel() const override;
+
   void UpdateFade(float fadePercentage, bool fadingIn);
 
 private:

Source/CesiumRuntime/Public/Cesium3DTileset.h

@@ -39,6 +39,7 @@ class CesiumViewExtension;
 struct FCesiumCamera;
 
 namespace Cesium3DTilesSelection {
+class GltfModifier;
 class Tileset;
 class TilesetView;
 class TileOcclusionRendererProxyPool;
@@ -1257,6 +1258,15 @@ class CESIUMRUNTIME_API ACesium3DTileset : public AActor {
    */
   void UpdateTransformFromCesium();
 
+  /**
+   * Sets the glTF modifier, an optional extension class that can edit
+   * each tile's glTF model after it has been loaded, before it can be
+   * displayed. Can only be called in the same engine tick after the tileset
+   * actor was spawned, or {@link RefreshTileset} was called.
+   */
+  void SetGltfModifier(
+      const std::shared_ptr<Cesium3DTilesSelection::GltfModifier>& InModifier);
+
 private:
   /**
    * The event handler for ACesiumGeoreference::OnEllipsoidChanged.
@@ -1371,6 +1381,8 @@ class CESIUMRUNTIME_API ACesium3DTileset : public AActor {
 
   int32 _tilesetsBeingDestroyed;
 
+  std::shared_ptr<Cesium3DTilesSelection::GltfModifier> _gltfModifier;
+
   friend class UnrealPrepareRendererResources;
   friend class UCesiumGltfPointsComponent;
 };

Source/CesiumRuntime/Public/CesiumLoadedTile.h

@@ -0,0 +1,21 @@
+// Copyright 2020-2024 CesiumGS, Inc. and Contributors
+
+#pragma once
+
+#include "UObject/ObjectMacros.h"
+
+#include "CesiumLoadedTile.generated.h"
+
+namespace CesiumGltf {
+struct Model;
+}
+
+UINTERFACE()
+class UCesiumLoadedTile : public UInterface {
+  GENERATED_BODY()
+};
+class ICesiumLoadedTile {
+  GENERATED_BODY()
+public:
+  virtual const CesiumGltf::Model* GetGltfModel() const = 0;
+};