Add check to disable LOD transitions in material layer

CHANGES.md

@@ -2,9 +2,14 @@
 
 ### ? - ?
 
+##### Breaking Changes :mega:
+
+- `UseLodTransitions` has been renamed to `EnableLodTransitions` on `Cesium3DTileset`.
+
 ##### Fixes :wrench:
 
-- Fixed an issue with pixel dithering artifacts that could appear on tilesets.
+- Fixed an issue with flickering pixel artifacts that could appear on tilesets.
+- Fixed an issue with dithering artifacts that would appear on tilesets when using non-temporal anti-aliasing methods for Forward Rendering.
 - Fixed an issue where DynamicPawn could get stuck after interrupting a flight from `UCesiumFlyToComponent`.
 
 ### v2.5.0 - 2024-05-01

Config/Engine.ini

@@ -152,3 +152,8 @@ AspectRatioAxisConstraint=AspectRatio_MaintainXFOV
 +EnumRedirects=(OldName="ECesiumMetadataPackedGpuType", NewName="ECesiumMetadataPackedGpuType_DEPRECATED", ValueChanges=(("None","Unknown_DEPRECATED"),("Uint8","Uint8_DEPRECATED"),("Float","Float_DEPRECATED")))
 
 +FunctionRedirects=(OldName="CesiumFeatureIdTextureBlueprintLibrary.GetTextureCoordinateIndex", NewName="CesiumFeatureIdTextureBlueprintLibrary.GetUnrealUVChannel")
+
++PropertyRedirects=(OldName="Cesium3DTileset.UseLodTransitions", NewName="EnableLodTransitions")
++FunctionRedirects=(OldName="Cesium3DTileset.GetUseLodTransitions", NewName="GetEnableLodTransitions")
++FunctionRedirects=(OldName="Cesium3DTileset.SetUseLodTransitions", NewName="SetEnableLodTransitions")
++PropertyRedirects=(OldName="Cesium3DTileset.SetUseLodTransitions.InUseLodTransitions", NewName="InEnableLodTransitions")

Source/CesiumRuntime/Private/Cesium3DTileset.cpp

@@ -87,7 +87,7 @@ ACesium3DTileset::ACesium3DTileset()
  _beforeMoviePreloadAncestors{PreloadAncestors},
  _beforeMoviePreloadSiblings{PreloadSiblings},
  _beforeMovieLoadingDescendantLimit{LoadingDescendantLimit},
- _beforeMovieUseLodTransitions{true},
+ _beforeMovieEnableLodTransitions{true},
 
  _tilesetsBeingDestroyed(0) {
 
@@ -272,9 +272,9 @@ void ACesium3DTileset::PostInitProperties() {
  }
 }
 
-void ACesium3DTileset::SetUseLodTransitions(bool InUseLodTransitions) {
- if (InUseLodTransitions != this->UseLodTransitions) {
- this->UseLodTransitions = InUseLodTransitions;
+void ACesium3DTileset::SetEnableLodTransitions(bool InEnableLodTransitions) {
+ if (InEnableLodTransitions != this->EnableLodTransitions) {
+ this->EnableLodTransitions = InEnableLodTransitions;
  this->DestroyTileset();
  }
 }
@@ -442,21 +442,21 @@ void ACesium3DTileset::PlayMovieSequencer() {
  this->_beforeMoviePreloadAncestors = this->PreloadAncestors;
  this->_beforeMoviePreloadSiblings = this->PreloadSiblings;
  this->_beforeMovieLoadingDescendantLimit = this->LoadingDescendantLimit;
- this->_beforeMovieUseLodTransitions = this->UseLodTransitions;
+ this->_beforeMovieEnableLodTransitions = this->EnableLodTransitions;
 
  this->_captureMovieMode = true;
  this->PreloadAncestors = false;
  this->PreloadSiblings = false;
  this->LoadingDescendantLimit = 10000;
- this->UseLodTransitions = false;
+ this->EnableLodTransitions = false;
 }
 
 void ACesium3DTileset::StopMovieSequencer() {
  this->_captureMovieMode = false;
  this->PreloadAncestors = this->_beforeMoviePreloadAncestors;
  this->PreloadSiblings = this->_beforeMoviePreloadSiblings;
  this->LoadingDescendantLimit = this->_beforeMovieLoadingDescendantLimit;
- this->UseLodTransitions = this->_beforeMovieUseLodTransitions;
+ this->EnableLodTransitions = this->_beforeMovieEnableLodTransitions;
 }
 
 void ACesium3DTileset::PauseMovieSequencer() { this->StopMovieSequencer(); }
@@ -1819,7 +1819,7 @@ void ACesium3DTileset::updateTilesetOptionsFromProperties() {
  options.enforceCulledScreenSpaceError = this->EnforceCulledScreenSpaceError;
  options.culledScreenSpaceError =
  static_cast<double>(this->CulledScreenSpaceError);
- options.enableLodTransitionPeriod = this->UseLodTransitions;
+ options.enableLodTransitionPeriod = this->EnableLodTransitions;
  options.lodTransitionLength = this->LodTransitionLength;
  // options.kickDescendantsWhileFadingIn = false;
 }
@@ -2071,7 +2071,7 @@ void ACesium3DTileset::Tick(float DeltaTime) {
  for (Cesium3DTilesSelection::Tile* pTile : pResult->tilesFadingOut) {
  Cesium3DTilesSelection::TileRenderContent* pRenderContent =
  pTile->getContent().getRenderContent();
- if (!this->UseLodTransitions ||
+ if (!this->EnableLodTransitions ||
  (pRenderContent &&
  pRenderContent->getLodTransitionFadePercentage() >= 1.0f)) {
  _tilesToHideNextFrame.push_back(pTile);
@@ -2080,7 +2080,7 @@ void ACesium3DTileset::Tick(float DeltaTime) {
 
  showTilesToRender(pResult->tilesToRenderThisFrame);
 
- if (this->UseLodTransitions) {
+ if (this->EnableLodTransitions) {
  TRACE_CPUPROFILER_EVENT_SCOPE(Cesium::UpdateTileFades)
 
  for (Cesium3DTilesSelection::Tile* pTile :
@@ -2180,7 +2180,7 @@ void ACesium3DTileset::PostEditChangeProperty(
  PropName ==
  GET_MEMBER_NAME_CHECKED(ACesium3DTileset, EnableOcclusionCulling) ||
  PropName ==
- GET_MEMBER_NAME_CHECKED(ACesium3DTileset, UseLodTransitions) ||
+ GET_MEMBER_NAME_CHECKED(ACesium3DTileset, EnableLodTransitions) ||
  PropName ==
  GET_MEMBER_NAME_CHECKED(ACesium3DTileset, ShowCreditsOnScreen) ||
  PropName == GET_MEMBER_NAME_CHECKED(ACesium3DTileset, Root) ||

Source/CesiumRuntime/Private/CesiumGltfComponent.cpp

@@ -3135,10 +3135,17 @@ static void loadPrimitiveGameThreadPart(
  EMaterialParameterAssociation::LayerParameter,
  0);
 
- // Initialize fade uniform to fully visible, in case LOD transitions
- // are off.
  int fadeLayerIndex = pCesiumData->LayerNames.Find("DitherFade");
  if (fadeLayerIndex >= 0) {
+ pMaterial->SetScalarParameterValueByInfo(
+ FMaterialParameterInfo(
+ "EnableLodTransitions",
+ EMaterialParameterAssociation::LayerParameter,
+ fadeLayerIndex),
+ pTilesetActor->GetEnableLodTransitions() ? 1.0f : 0.0f);
+
+ // Initialize fade uniforms to fully visible, in case LOD transitions
+ // are off.
  pMaterial->SetScalarParameterValueByInfo(
  FMaterialParameterInfo(
  "FadePercentage",
@@ -3147,7 +3154,7 @@ static void loadPrimitiveGameThreadPart(
  1.0f);
  pMaterial->SetScalarParameterValueByInfo(
  FMaterialParameterInfo(
- "FadingType",
+ "FadeDirection",
  EMaterialParameterAssociation::LayerParameter,
  fadeLayerIndex),
  0.0f);

Source/CesiumRuntime/Public/Cesium3DTileset.h

@@ -425,13 +425,14 @@ class CESIUMRUNTIME_API ACesium3DTileset : public AActor {
  * This will cause more tiles to be loaded, but helps to avoid holes and
  * provides a more consistent mesh, which may be helpful for physics.
  *
- * Note that this will always be disabled if UseLodTransitions is set to true.
+ * Note that this will always be disabled if Enable Lod Transitions is set to
+ * true.
  */
  UPROPERTY(
  EditAnywhere,
  BlueprintReadWrite,
  Category = "Cesium|Tile Culling",
- Meta = (EditCondition = "!UseLodTransitions", EditConditionHides))
+ Meta = (EditCondition = "!EnableLodTransitions", EditConditionHides))
  bool EnableFrustumCulling = true;
 
  /**
@@ -442,13 +443,14 @@ class CESIUMRUNTIME_API ACesium3DTileset : public AActor {
  * of the camera above the ground, tiles that are far away (close to
  * the horizon) will be culled when this flag is enabled.
  *
- * Note that this will always be disabled if UseLodTransitions is set to true.
+ * Note that this will always be disabled if Enable Lod Transitions is set to
+ * true.
  */
  UPROPERTY(
  EditAnywhere,
  BlueprintReadWrite,
  Category = "Cesium|Tile Culling",
- Meta = (EditCondition = "!UseLodTransitions", EditConditionHides))
+ Meta = (EditCondition = "!EnableLodTransitions", EditConditionHides))
  bool EnableFogCulling = true;
 
  /**
@@ -616,29 +618,34 @@ class CESIUMRUNTIME_API ACesium3DTileset : public AActor {
  FCompletedLoadTrigger OnTilesetLoaded;
 
  /**
- * Use a dithering effect when transitioning between tiles of different LODs.
+ * Whether to enable a dithering effect when transitioning between tiles of
+ * different LODs.
  *
  * When this is set to true, Frustrum Culling and Fog Culling are always
  * disabled.
+ *
+ * When Forward Rendering is enabled for the project, LOD transitions are
+ * only compatible when used with temporal anti-aliasing methods. Setting this
+ * to true for other methods will result in dithering artifacts.
  */
  UPROPERTY(
  EditAnywhere,
- BlueprintGetter = GetUseLodTransitions,
- BlueprintSetter = SetUseLodTransitions,
+ BlueprintGetter = GetEnableLodTransitions,
+ BlueprintSetter = SetEnableLodTransitions,
  Category = "Cesium|Rendering")
- bool UseLodTransitions = false;
+ bool EnableLodTransitions = false;
 
  /**
- * How long dithered LOD transitions between different tiles should take, in
+ * How long the LOD transitions between different tiles should take, in
  * seconds.
  *
- * Only relevant if UseLodTransitions is true.
+ * Only relevant if Enable Lod Transitions is true.
  */
  UPROPERTY(
  EditAnywhere,
  BlueprintReadWrite,
  Category = "Cesium|Rendering",
- meta = (EditCondition = "UseLodTransitions", EditConditionHides))
+ meta = (EditCondition = "EnableLodTransitions", EditConditionHides))
  float LodTransitionLength = 0.5f;
 
 private:
@@ -904,10 +911,10 @@ class CESIUMRUNTIME_API ACesium3DTileset : public AActor {
  float GetLoadProgress() const { return LoadProgress; }
 
  UFUNCTION(BlueprintGetter, Category = "Cesium")
- bool GetUseLodTransitions() const { return UseLodTransitions; }
+ bool GetEnableLodTransitions() const { return EnableLodTransitions; }
 
  UFUNCTION(BlueprintSetter, Category = "Cesium")
- void SetUseLodTransitions(bool InUseLodTransitions);
+ void SetEnableLodTransitions(bool InEnableLodTransitions);
 
  UFUNCTION(BlueprintGetter, Category = "Cesium")
  ETilesetSource GetTilesetSource() const { return TilesetSource; }
@@ -1207,7 +1214,7 @@ class CESIUMRUNTIME_API ACesium3DTileset : public AActor {
  bool _beforeMoviePreloadAncestors;
  bool _beforeMoviePreloadSiblings;
  int32_t _beforeMovieLoadingDescendantLimit;
- bool _beforeMovieUseLodTransitions;
+ bool _beforeMovieEnableLodTransitions;
 
  bool _scaleUsingDPI;