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  3. UMaterialExpression

UMaterialExpression

Unreal Engine C++ API Reference > Runtime > Engine > Materials

Inheritance Hierarchy

References

   
Module Engine
Header /Engine/Source/Runtime/Engine/Classes/Materials/MaterialExpression.h
Include #include "Materials/MaterialExpression.h"

Syntax

class UMaterialExpression : public UObject

Variables

  Type Name Description
Public variable uint32: 1 bCollapsed If true, show a collapsed version of the node
Public variable uint32: 1 bCommentBubbleVisible If true, the comment bubble will be visible in the graph editor
Public variable uint32: 1 bHidePreviewWindow If true, do not render the preview window for the expression
Public variable uint8: 1 bIsParameterExpression Indicates that this is a 'parameter' type of expression and should always be loaded (ie not cooked away) because we might want the default parameter.
Public variable uint32: 1 bNeedToUpdatePreview If true, we should update the preview next render. This is set when changing bRealtimePreview.
Public variable uint32: 1 bRealtimePreview Set to true by RecursiveUpdateRealtimePreview() if the expression's preview needs to be updated in realtime in the material editor.
Public variable uint32: 1 bShaderInputData Whether the node represents an input to the shader or not. Used to color the node's background.
Public variable uint32: 1 bShowInputs Whether to draw the expression's inputs.
Public variable uint32: 1 bShowMaskColorsOnPin If true, changes the pin color to match the output mask
Public variable uint32: 1 bShowOutputNameOnPin If true, use the output name as the label for the pin
Public variable uint32: 1 bShowOutputs Whether to draw the expression's outputs.
Protected variable TArray< FExpressionInput * > CachedInputs Caches the list of expression inputs this expression has.
Public variable FString Desc A description that level designers can add (shows in the material editor UI).
Public variable TObjectPtr< class UMaterialFunction > Function The material function that this expression is being used with, if any.
Public variable TObjectPtr< UEdGraphNode > GraphNode Expression's Graph representation
Public variable FString LastErrorText Text of last error for this expression
Public variable TObjectPtr< class UMaterial > Material The material that this expression is currently being compiled in.
Public variable int32 MaterialExpressionEditorX  
Public variable int32 MaterialExpressionEditorY  
Public variable FGuid MaterialExpressionGuid GUID to uniquely identify this node, to help the tutorials out
Public variable TArray< FText > MenuCategories Localized categories to sort this expression into...
Public variable int32 NumExecutionInputs Number of expressions connected to this expression's execution input
Public variable TArray< FExpressionOutput > Outputs The expression's outputs, which are set in default properties by derived classes.
Public variable TObjectPtr< UMaterialExpression > SubgraphExpression If exists, expresssion containing this expression within its subgraph.

Constructors

  Type Name Description
Public function  

UMaterialExpression ( const FObjectInitializer& ObjectInitializer
)

  

Functions

  Type Name Description
Public function Virtual bool If true, discards the output index when caching this expression which allows more cases to re-use the output instead of adding a separate instruction
Public function Virtual Const bool Returns true if GetReferencedTexture() can ever return a valid pointer.
Public function Virtual Const bool Can this node be renamed?
Public function Virtual Const bool  
Public function Virtual int32

Compile ( FMaterialCompiler* Compiler,
int32 OutputIndex
)

 Create the new shader code chunk needed for the Abs expression
Public function Virtual int32

CompilePreview ( FMaterialCompiler* Compiler,
int32 OutputIndex
)

  
Public function Virtual int32

CompilerError ( FMaterialCompiler* Compiler,
const TCHAR* pcMessage
)

  
Public function Virtual void

ConnectExpression ( FExpressionInput* Input,
int32 OutputIndex
)

 Connects the specified input expression to the specified output of this expression.
Public function void

ConnectToPreviewMaterial ( UMaterial* InMaterial,
int32 OutputIndex
)

 Connects the specified output to the passed material for previewing.
Public function bool

ContainsInputLoop ( const bool bStopOnFunctionCall
)

 Checks whether any inputs to this expression create a loop
Public function bool

ContainsInputLoop ( TSet< UMaterialExpression* >& VisitedExpressions,
const bool bStopOnFunctionCall
)

 This overload accepts the set of visited expressions to avoid visiting them again when checking at once whether multiple expressions contain a loop.
Public function Static void

CopyMaterialExpressions ( const TArray< class UMaterialExpression* >& SrcExpressions,
const TArray< class UMaterialExpressionComment* >& SrcExpressionComments,
UMaterial* Material,
UMaterialFunction* Function,
TArray< class UMaterialExpression* >& OutNewExpressions,
TArray< class UMaterialExpression* >& OutNewComments
)

 Copy the SrcExpressions into the specified material, preserving internal references.
Public function Virtual void

GatherStrataMaterialInfo ( FStrataMaterialInfo& StrataMaterialInfo,
int32 OutputIndex
)

 Recursively parse nodes outputing strata material in order to gather all the possible shading models used in a material graph output a Strata material.
Public function Virtual Const bool

GenerateHLSLExpression ( FMaterialHLSLGenerator& Generator,
UE::HLSLTree::FScope& Scope,
int32 OutputIndex,
UE::HLSLTree::FExpression const*& OutExpression
)

  
Public function Virtual Const bool A given UMaterial implementation should implement at least one of these methods in order to generate HLSL code It's valid to implement more than one, if the expression can be used in multiple ways.
Public function bool Recursively gets a list of all expressions that are connected to this Checks for repeats so that it can't end up in an infinite loop
Public function Const UObject *  
Public function Const FString  
Public function Virtual Const void

GetCaption ( TArray< FString >& OutCaptions
)

 Returns the text to display on the material expression (in the material editor).
Public function Virtual void

GetConnectorToolTip ( int32 InputIndex,
int32 OutputIndex,
TArray< FString >& OutToolTip
)

 Get a tooltip for the specified connector.
Public function Virtual Const FText  
Public function Virtual Const FText  
Public function Virtual Const FString Get a single line description of the material expression (used for lists)
Public function Virtual Const FString Returns the current 'name' of the node (typically a parameter name).
Public function Virtual void  
Public function Virtual void

GetExpressionToolTip ( TArray< FString >& OutToolTip
)

 Get a tooltip for the expression itself.
Public function Virtual Const int32  
Public function Virtual FExpressionInput *

GetInput ( int32 InputIndex
)

  
Public function Virtual Const FName

GetInputName ( int32 InputIndex
)

  
Public function Virtual FString

GetInputPinDefaultValue ( int32 PinIndex
)

  
Public function Virtual TArray< FProperty * >

GetInputPinProperty ( int32 PinIndex
)

 Find the property that is associated with the input pin.
Public function Virtual FName

GetInputPinSubCategory ( int32 PinIndex
)

  
Public function Virtual UObject *

GetInputPinSubCategoryObject ( int32 PinIndex
)

  
Public function Virtual TArrayView< FExpressionInput * > Get the expression inputs supported by this expression (Note: property inputs NOT included).
Public function Virtual uint32

GetInputType ( int32 InputIndex
)

  
Public function Virtual Const FText Returns the keywords that should be used when searching for this expression
Public function Virtual int Returns the amount of padding to use for the label.
Public function Virtual Const void

GetLandscapeLayerNames ( TArray< FName >& OutLayers
)

  
Public function Virtual FGuid & Return the material expression guid.
Public function Virtual TArray< FExpressionOutput > & Get the outputs supported by this expression.
Public function Virtual uint32

GetOutputType ( int32 OutputIndex
)

  
Public function Virtual FGuid & Callback to access derived classes' parameter expression id.
Public function Virtual Const FName  
Public function Const EMaterialParameterType  
Public function Virtual Const bool  
Public function Virtual Const FText  
Public function Virtual Const TArray< FProperty * >  
Public function Virtual Const UObject * Callback to get any texture reference this expression emits.
Public function Virtual Const void Fill the array with all textures dependence that should trig a recompile of the material.
Public function Virtual Const int32 Get the width required by this expression (in the material editor).
Public function Virtual Const bool Parameter Name functions, this is requires as multiple class have ParameterName but are not UMaterialExpressionParameter due to class hierarchy.
Public function Virtual Const bool  
Public function Virtual Const bool  
Public function Virtual bool  
Public function Static void  
Public function Virtual bool

IsExpressionConnected ( FExpressionInput* Input,
int32 OutputIndex
)

 Check if input exppresion is directly connected to the material.
Public function Virtual Const bool

IsInputConnectionRequired ( int32 InputIndex
)

  
Public function Virtual bool

IsResultMaterialAttributes ( int32 OutputIndex
)

 Marks certain expression types as outputting material attributes.
Public function Virtual bool

IsResultStrataMaterial ( int32 OutputIndex
)

 Marks certain expression types as outputting Strata material.
Public function Const bool  
Public function Virtual bool

MatchesSearchQuery ( const TCHAR* SearchQuery
)

 MatchesSearchQuery: Check this expression to see if it matches the search query
Public function Virtual bool  
Public function Virtual void

PinDefaultValueChanged ( int32 PinIndex,
const FString& DefaultValue
)

  
Public function Virtual void

PostCopyNode ( const TArray< UMaterialExpression* >& CopiedExpressions
)

 Called after a node copy, once the Material and Function properties are set correctly and that all new expressions are added to Material->Expressions
Public function Virtual void

SetEditableName ( const FString& NewName
)

 Sets the current 'name' of the node (typically a parameter name) Only valid to call on a node that previously returned CanRenameNode() = true.
Public function Virtual void

SetParameterName ( const FName& Name
)

  
Public function Virtual bool

SetParameterValue ( const FName& Name,
const FMaterialParameterMetadata& Meta,
EMaterialExpressionSetParameterValueFlags Flags
)

  
Public function Virtual FStrataOperator * A starta material is a tree with FrontMateiral being its root and BSDF being leaves, with operators in the middle.
Public function void

UpdateMaterialExpressionGuid ( bool bForceGeneration,
bool bAllowMarkingPackageDirty
)

 Generates a GUID for this expression if one doesn't already exist.
Public function void

UpdateParameterGuid ( bool bForceGeneration,
bool bAllowMarkingPackageDirty
)

 Generates a GUID for the parameter expression if one doesn't already exist and we are one.
Public function Virtual Const bool  
Public function Virtual Const bool  
Public function Virtual void

ValidateParameterName ( const bool bAllowDuplicateName
)

  
Public function void Asserts if the expression is not contained by its Material or Function's expressions array.

Overridden from UObject

  Type Name Description
Public function Virtual Const bool

CanEditChange ( const FProperty* InProperty
)

 Called by the editor to query whether a property of this object is allowed to be modified.
Public function Virtual bool

Modify ( bool bAlwaysMarkDirty
)

 Note that the object will be modified.
Public function Virtual void

PostDuplicate ( bool bDuplicateForPIE
)

 Called after duplication & serialization and before PostLoad.
Public function Virtual void

PostEditChangeProperty ( FPropertyChangedEvent& PropertyChangedEvent
)

 Called when a property on this object has been modified externally
Public function Virtual void Called after importing property values for this object (paste, duplicate or .t3d import) Allow the object to perform any cleanup for properties which shouldn't be duplicated or are unsupported by the script serialization
Public function Virtual void Called after the C++ constructor and after the properties have been initialized, including those loaded from config.
Public function Virtual void Do any object-specific cleanup required immediately after loading an object.
Public function Virtual void Handles reading, writing, and reference collecting using FArchive.

Classes

  Type Name Description
Public struct FContainsInputLoopInternalExpressionStack    

Constants

Name Description
CompileExecutionOutputIndex  

Deprecated Functions

  Type Name Description
Public function const TArray< FExpressionInput * > Use GetInputsView() instead.

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