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  3. UUsdAssetCache3

UUsdAssetCache3

This class is an asset that can be created via the Content Browser and assigned to AUsdStageActors.

API > API/Plugins > API/Plugins/USDClasses

This class is an asset that can be created via the Content Browser and assigned to AUsdStageActors.

Its main purpose is to track generated assets based on the hash of the source prim data: Whenever the AUsdStageActor needs to generate e.g. a MaterialInstance, it will first hash the Material prim, and check whether its UUsdAssetCache3 already has an asset of that class for the resulting hash.

The cache can then be shared by multiple AUsdStageActors to prevent recreating UObjects from identical, already translated prim data.

A "Default Asset Cache" can be set on the project settings, and will be automatically used for any AUsdStageActor that hasn't had an asset cache manually set beforehand.

   
Name UUsdAssetCache3
Type class
Header File /Engine/Plugins/Runtime/USDCore/Source/USDClasses/Public/USDAssetCache3.h
Include Path #include "USDAssetCache3.h"

Syntax

UCLASS (MinimalAPI, BlueprintType, Blueprintable,  
       Meta=(DisplayName="USD Asset Cache", ScriptName="UsdAssetCache"))  
class UUsdAssetCache3 : public UObject

Inheritance Hierarchy

Constructors

Name Remarks Include Path Unreal Specifiers

UUsdAssetCache3()

   USDAssetCache3.h  

Structs

Name Remarks
FUsdScopedReferencer The UUsdAssetCache3 can track all the UObjects that are referencing assets, so that it knows when to discard an unreferenced asset.

Variables

Public

Name Type Remarks Include Path Unreal Specifiers
AssetDirectory FDirectoryPath Content directory where the asset cache will place newly created assets. USDAssetCache3.h
  • EditAnywhere
  • BlueprintReadWrite
  • Category="Storage"
  • Meta=(ContentDir, NoResetToDefault)
bCleanUpUnreferencedAssets bool If this is true, every time a UsdStageActor using this asset cache closes a stage or swaps asset caches it will attempt to call DeleteUnreferencedAssets, potentially dropping any unreferenced asset, due to this operation or previous ones. USDAssetCache3.h
  • EditAnywhere
  • BlueprintReadWrite
  • Category="Cleanup"
bOnlyHandleAssetsWithinAssetDirectory bool When true, it means the asset cache will only ever return assets that are currently inside of the AssetDirectory folder. USDAssetCache3.h
  • EditAnywhere
  • BlueprintReadWrite
  • Category="Storage"
HashToAssetPaths TMap< FString, FSoftObjectPath > This is the main internal property that maps hashes to asset paths. USDAssetCache3.h
  • EditAnywhere
  • BlueprintReadWrite
  • Category="Storage"

Protected

Name Type Remarks Include Path Unreal Specifiers
ActiveAssets TSet< FSoftObjectPath > This member is mostly used by the UsdStageImporter: Assets are added to it whenever they are cached or fetched, and reset by calling MarkAssetsAsStale(). USDAssetCache3.h  
AssetPathToHashes TMap< FSoftObjectPath, FString > Reverse map, to speed up queries like GetHashForAsset and IsAssetTrackedByCache. Should always match HashToAssetPaths. USDAssetCache3.h  
bPendingCleanup bool   USDAssetCache3.h  
CurrentScopedReferencer const UObject * When this is set to something, we will automatically flag it as a referencer of any cached/touched asset. USDAssetCache3.h  
DeletableAssetKeys TSet< FObjectKey >   USDAssetCache3.h  
HashToReferencer TMap< FString, TArray< FObjectKey > >   USDAssetCache3.h  
ReferencerToHash TMap< FObjectKey, TArray< FString > >   USDAssetCache3.h  
RWLock FRWLock   USDAssetCache3.h  
TransientObjectStorage TMap< FString, TObjectPtr< UObject > > If we're a transient asset cache, our assets will be placed on the transient package and there wouldn't necessarily be anything holding a strong reference to them. USDAssetCache3.h
  • Transient

Functions

Public

Name Remarks Include Path Unreal Specifiers

bool AddAssetReferencer ( const UObject* Asset,
const UObject* Referencer
)

 Adds a new UObject referencer to a particular asset, returning true if the operation succeeded. USDAssetCache3.h
  • BlueprintCallable
  • Category="Caching"
  • Meta=(CallInEditor="true")

void CacheAsset ( const FString& Hash,
const FSoftObjectPath& AssetPath,
const UObject* Referencer
)

 Adds an existing asset to the cache attached to a particular hash, and optionally registering a referencer USDAssetCache3.h
  • BlueprintCallable
  • Category="USD"
  • Meta=(CallInEditor="true")

void DeleteUnreferencedAssets ( const bool bShowConfirmation
)

 Deletes all assets that: USDAssetCache3.h
  • BlueprintCallable
  • Category="Cleanup"
  • Meta=(CallInEditor="true")
This is the same as calling DeleteUnreferencedAssets and providing true for bShowConfirmation. USDAssetCache3.h
  • BlueprintCallable
  • Category="Cleanup"
  • Meta=(CallInEditor="true", DisplayName="Delete Unreferenced Assets")

TSet< FSoftObjectPath > GetActiveAssets()

   USDAssetCache3.h  

TMap< FString, FSoftObjectPath > GetAllTrackedAssets()

 Returns a copy of the internal mapping between hashes and asset paths USDAssetCache3.h
  • BlueprintCallable
  • Category="USD"
  • Meta=(CallInEditor="true")

T * GetCachedAsset ( const FString& Hash
)

 Templated version of GetCachedAsset for convenience USDAssetCache3.h  

UObject * GetCachedAsset ( const FString& Hash
) const

 Returns the asset associated with a particular Hash, if any. USDAssetCache3.h
  • BlueprintCallable
  • Category="USD"
  • Meta=(CallInEditor="true")
Returns the internal FSoftObjectPath associated with Hash, without trying to load the asset. USDAssetCache3.h
  • BlueprintCallable
  • Category="USD"
  • Meta=(CallInEditor="true")

FString GetHashForAsset ( const FSoftObjectPath& AssetPath
) const

 Returns the hash associated with a particular asset, or the empty string if there isn't any. USDAssetCache3.h
  • BlueprintCallable
  • Category="USD"
  • Meta=(CallInEditor="true")

int32 GetNumAssets()

 Returns the total number of cached asset paths, whether these resolve to assets or not USDAssetCache3.h
  • BlueprintCallable
  • Category="USD"
  • Meta=(CallInEditor="true")

UObject * GetOrCreateCachedAsset ( const FString& Hash,
UClass* Class,
const FString& DesiredName,
int32 DesiredFlags,
bool& bOutCreatedAsset,
const UObject* Referencer
)

 Returns the cached UObject of the provided Class for the provided Hash if one exists. USDAssetCache3.h
  • BlueprintCallable
  • Category="USD"
  • Meta=(CallInEditor="true")

T * GetOrCreateCachedAsset ( const FString& Hash,
FString DesiredName,
EObjectFlags DesiredFlags,
bool* bOutCreatedAsset,
const UObject* Referencer
)

 Templated version of GetOrCreateCachedAsset for convenience USDAssetCache3.h  

T * GetOrCreateCustomCachedAsset ( const FString& Hash,
FString DesiredName,
EObjectFlags DesiredFlags,
TFunctionRef< UObject*(UPackage*PackageOuter, FName SanitizedName, EObjectFlags FlagsToUse...,
bool* bOutCreatedAsset,
const UObject* Referencer
)

 Templated version of GetOrCreateCachedAsset for convenience USDAssetCache3.h  

UObject * GetOrCreateCustomCachedAsset ( const FString& Hash,
UClass* Class,
const FString& DesiredName,
EObjectFlags DesiredFlags,
TFunctionRef< UObject*(UPackage*PackageOuter, FName SanitizedName, EObjectFlags FlagsToUse...,
bool* bOutCreatedAsset,
const UObject* Referencer
)

 For most asset types GetOrCreateCachedAsset should suffice: It will internally call NewObject(). USDAssetCache3.h  

bool IsAssetDeletable ( const UObject* Asset
) const

 Returns whether a particular asset is currently marked as deletable or not USDAssetCache3.h
  • BlueprintCallable
  • Category="USD"
  • Meta=(CallInEditor="true")

bool IsAssetTrackedByCache ( const FSoftObjectPath& AssetPath
) const

 Returns true if this asset is currently tracked by the asset cache's main hash to asset maps USDAssetCache3.h
  • BlueprintCallable
  • Category="USD"
  • Meta=(CallInEditor="true")
The same as GetAllTrackedAssets, except that it will automatically try loading all the asset paths before returning, which should be convenient for Python or Blueprint callers. USDAssetCache3.h
  • BlueprintCallable
  • Category="USD"
  • Meta=(CallInEditor="true")

void MarkAssetsAsStale()

   USDAssetCache3.h  

void OnRegistryAssetRenamed ( const FAssetData& NewAssetData,
const FString& OldName
)

   USDAssetCache3.h  

bool RemoveAllAssetReferencers()

 Removes all UObject referencer from all tracked assets, returning true if anything was removed. USDAssetCache3.h
  • BlueprintCallable
  • Category="USD"
  • Meta=(CallInEditor="true")

bool RemoveAllReferencerAssets ( const UObject* Referencer
)

 Removes a particular UObject referencer from all tracked assets, returning true if anything was removed. USDAssetCache3.h
  • BlueprintCallable
  • Category="USD"
  • Meta=(CallInEditor="true")

bool RemoveAllReferencersForAsset ( const UObject* Asset
)

 Removes all UObject referencers from a particular asset, returning true if anything was removed. USDAssetCache3.h
  • BlueprintCallable
  • Category="USD"
  • Meta=(CallInEditor="true")

bool RemoveAssetReferencer ( const UObject* Asset,
const UObject* Referencer
)

 Removes an UObject referencer from a particular asset, returning true if anything was removed. USDAssetCache3.h
  • BlueprintCallable
  • Category="USD"
  • Meta=(CallInEditor="true")

void RequestDelayedAssetAutoCleanup()

   USDAssetCache3.h  
Checks the current AssetDirectory for any new assets that were generated from USD, and automatically caches them if possible. USDAssetCache3.h
  • BlueprintCallable
  • Category="Storage"
  • Meta=(CallInEditor="true")

void SetAssetDeletable ( const UObject* Asset,
bool bIsDeletable
)

 Sets a particular asset as deletable or not. USDAssetCache3.h
  • BlueprintCallable
  • Category="USD"
  • Meta=(CallInEditor="true")

const UObject * SetCurrentScopedReferencer ( const UObject* NewReferencer
)

   USDAssetCache3.h  
Removes all info about the asset associated with Hash from this cache, if there is any. USDAssetCache3.h
  • BlueprintCallable
  • Category="USD"
  • Meta=(CallInEditor="true")

void TouchAsset ( const FString& Hash,
const UObject* Referencer
)

   USDAssetCache3.h  

void TouchAssetPath ( const FSoftObjectPath& AssetPath,
const UObject* Referencer
)

   USDAssetCache3.h  

Overridden from UObject

Name Remarks Include Path Unreal Specifiers

virtual void BeginDestroy()

   USDAssetCache3.h  

virtual void PostEditChangeProperty ( FPropertyChangedEvent& PropertyChangedEvent
)

   USDAssetCache3.h  

virtual void PostLoad()

   USDAssetCache3.h  

virtual void Serialize ( FArchive& Ar
)

   USDAssetCache3.h  

Protected

Name Remarks Include Path Unreal Specifiers

void AddReferenceInternal ( const FString& Hash,
const UObject* Referencer
)

   USDAssetCache3.h  

void ForceValidAssetDirectoryInternal ( bool bEmitWarning
)

   USDAssetCache3.h  

bool IsTransientCache()

   USDAssetCache3.h  

bool RemoveAllAssetReferencersInternal ( const FString& Hash
)

   USDAssetCache3.h  

FSoftObjectPath StopTrackingAssetInternal ( const FString& Hash
)

   USDAssetCache3.h  

void TouchAssetInternal ( const FSoftObjectPath& AssetPath,
const UObject* Referencer
)

   USDAssetCache3.h  

void TryCachingAssetFromAssetUserData ( const FAssetData& NewAssetData
)

   USDAssetCache3.h  

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