Working on editing MG

Plugins/BlueprintMCP/Source/BlueprintMCP/Handlers/GraphPin_Connect.h

@@ -34,22 +34,22 @@ class UMCP_GraphPin_Connect : public UObject, public IMCPHandler
 	GENERATED_BODY()
 
 public:
-	UPROPERTY(meta=(Description="Blueprint name or package path"))
+	UPROPERTY(meta=(Description="Path to a graph, e.g. /Game/Foo,graph:EventGraph or /Game/Materials/M_Test"))
-	FString Blueprint;
+	FString Graph;
 
 	UPROPERTY(meta=(Description="Array of {sourcePin, targetPin} objects. Each pin is a path like node:MyNode,pin:Output"))
 	FMCPJsonArray Connections;
 
 	virtual FString GetDescription() const override
 	{
-		return TEXT("Connect pins between nodes in a Blueprint graph.");
+		return TEXT("Connect pins between nodes in a graph (Blueprint or Material).");
 	}
 
 	virtual void Handle(FStringBuilderBase& Result) override
 	{
 		MCPFetcher F(Result);
-		UBlueprint* BP = F.Walk(Blueprint).Cast<UBlueprint>();
+		UEdGraph* G = F.Walk(Graph).ToGraph().Cast<UEdGraph>();
-		if (!BP) return;
+		if (!G) return;
 
 		F.PreEdit();
 
@@ -62,15 +62,15 @@ public:
 			if (!MCPUtils::PopulateFromJson(FConnectPinsEntry::StaticStruct(), &Entry, ConnVal, Result))
 				continue;
 
-			MCPFetcher FS(Result, BP);
+			MCPFetcher FS(Result, G);
 			UEdGraphPin* SourcePin = FS.Walk(Entry.SourcePin).Cast<UEdGraphPin>();
 			if (!SourcePin) continue;
 
-			MCPFetcher FT(Result, BP);
+			MCPFetcher FT(Result, G);
 			UEdGraphPin* TargetPin = FT.Walk(Entry.TargetPin).Cast<UEdGraphPin>();
 			if (!TargetPin) continue;
 
-			const UEdGraphSchema* Schema = SourcePin->GetOwningNode()->GetGraph()->GetSchema();
+			const UEdGraphSchema* Schema = G->GetSchema();
 			const FPinConnectionResponse Response = Schema->CanCreateConnection(SourcePin, TargetPin);
 			if (Response.Response == CONNECT_RESPONSE_DISALLOW)
 			{

Plugins/BlueprintMCP/Source/BlueprintMCP/Handlers/GraphPin_Disconnect.h

@@ -33,23 +33,23 @@ class UMCP_GraphPin_Disconnect : public UObject, public IMCPHandler
 	GENERATED_BODY()
 
 public:
-	UPROPERTY(meta=(Description="Blueprint name or package path"))
+	UPROPERTY(meta=(Description="Path to a graph, e.g. /Game/Foo,graph:EventGraph or /Game/Materials/M_Test"))
-	FString Blueprint;
+	FString Graph;
 
 	UPROPERTY(meta=(Description="Array of {pin, targetPin?} objects. Each pin is a path like node:MyNode,pin:Output. If targetPin is omitted, all connections on the pin are broken."))
 	FMCPJsonArray Disconnections;
 
 	virtual FString GetDescription() const override
 	{
-		return TEXT("Disconnect pins in a Blueprint graph. "
+		return TEXT("Disconnect pins in a graph (Blueprint or Material). "
 			"Can disconnect a specific link or all links on a pin.");
 	}
 
 	virtual void Handle(FStringBuilderBase& Result) override
 	{
 		MCPFetcher F(Result);
-		UBlueprint* BP = F.Walk(Blueprint).Cast<UBlueprint>();
+		UEdGraph* G = F.Walk(Graph).ToGraph().Cast<UEdGraph>();
-		if (!BP) return;
+		if (!G) return;
 
 		F.PreEdit();
 
@@ -61,7 +61,7 @@ public:
 			FDisconnectPinEntry Entry;
 			if (!MCPUtils::PopulateFromJson(FDisconnectPinEntry::StaticStruct(), &Entry, DiscVal, Result)) continue;
 
-			MCPFetcher FP(Result, BP);
+			MCPFetcher FP(Result, G);
 			UEdGraphPin* Pin = FP.Walk(Entry.Pin).Cast<UEdGraphPin>();
 			if (!Pin) continue;
 
@@ -69,7 +69,7 @@ public:
 
 			if (!Entry.TargetPin.IsEmpty())
 			{
-				MCPFetcher FT(Result, BP);
+				MCPFetcher FT(Result, G);
 				UEdGraphPin* Target = FT.Walk(Entry.TargetPin).Cast<UEdGraphPin>();
 				if (!Target) continue;
 

Plugins/BlueprintMCP/Source/BlueprintMCP/Handlers/GraphPin_SetDefault.h

@@ -76,23 +76,28 @@ public:
 				continue;
 			}
 
-			const UEdGraphSchema_K2* Schema = Cast<UEdGraphSchema_K2>(Node->GetGraph()->GetSchema());
+			Pin->Modify();
-			check(Schema);
 
-			// Parse and validate the value before applying.
+			// K2 schemas support validation before setting; other schemas (e.g. material) don't.
+			const UEdGraphSchema_K2* K2Schema = Cast<UEdGraphSchema_K2>(Node->GetGraph()->GetSchema());
+			if (K2Schema)
+			{
 				FString UseDefaultValue;
 				TObjectPtr<UObject> UseDefaultObject = nullptr;
 				FText UseDefaultText;
-			Schema->GetPinDefaultValuesFromString(Pin->PinType, Node, Entry.Value, UseDefaultValue, UseDefaultObject, UseDefaultText, false);
+				K2Schema->GetPinDefaultValuesFromString(Pin->PinType, Node, Entry.Value, UseDefaultValue, UseDefaultObject, UseDefaultText, false);
-			FString Error = Schema->IsPinDefaultValid(Pin, UseDefaultValue, UseDefaultObject, UseDefaultText);
+				FString Error = K2Schema->IsPinDefaultValid(Pin, UseDefaultValue, UseDefaultObject, UseDefaultText);
 				if (!Error.IsEmpty())
 				{
 					Result.Appendf(TEXT("error: %s: %s\n"), *MCPUtils::FormatName(Pin), *Error);
 					continue;
 				}
-
+				K2Schema->TrySetDefaultValue(*Pin, Entry.Value);
-			Pin->Modify();
+			}
-			Schema->TrySetDefaultValue(*Pin, Entry.Value);
+			else
+			{
+				Node->GetGraph()->GetSchema()->TrySetDefaultValue(*Pin, Entry.Value);
+			}
 
 			SuccessCount++;
 			ModifiedNodes.Add(Node);

Plugins/BlueprintMCP/Source/BlueprintMCP/Private/BlueprintExporter.cpp

@@ -10,6 +10,7 @@
 #include "K2Node_VariableGet.h"
 #include "K2Node_CallFunction.h"
 #include "K2Node_FunctionEntry.h"
+#include "MaterialGraph/MaterialGraphNode.h"
 
 static FString WrapText(const FString& Text, int32 ColLimit, const FString& Prefix)
 {
@@ -232,6 +233,9 @@ void FlxBlueprintExporter::EmitNode(UEdGraphNode* Node)
 
 	Output.Appendf(TEXT("\nnode %s: %s\n"), *MCPUtils::FormatName(Node), *MCPUtils::FormatNodeTitle(Node));
 
+	// Emit material expression properties (if applicable).
+	EmitMaterialProperties(Node, Output, true);
+
 	// Emit input data pins.
 	for (UEdGraphPin* Pin : FilterPins(Node, EGPD_Input))
 	{
@@ -274,6 +278,39 @@ void FlxBlueprintExporter::EmitNode(UEdGraphNode* Node)
 	}
 }
 
+void FlxBlueprintExporter::EmitMaterialProperty(UMaterialExpression* Expression, FProperty* Prop, FStringBuilderBase& Out)
+{
+	FString ValueStr = MCPUtils::GetPropertyValueText(Expression, Prop);
+	ValueStr.ReplaceInline(TEXT("\r\n"), TEXT(" "));
+	ValueStr.ReplaceInline(TEXT("\n"), TEXT(" "));
+	if (ValueStr.Len() > 80)
+		ValueStr = ValueStr.Left(80) + TEXT("...");
+
+	bool bEditable = !Prop->HasAnyPropertyFlags(CPF_EditConst);
+	Out.Appendf(TEXT("    %s %s %s = %s\n"),
+		bEditable ? TEXT("editable") : TEXT("readonly"),
+		*MCPUtils::FormatPropertyType(Prop),
+		*MCPUtils::FormatName(Prop),
+		*ValueStr);
+}
+
+void FlxBlueprintExporter::EmitMaterialProperties(UEdGraphNode* Node, FStringBuilderBase& Out, bool bPrimary)
+{
+	UMaterialGraphNode* MatNode = Cast<UMaterialGraphNode>(Node);
+	if (!MatNode || !MatNode->MaterialExpression) return;
+
+	UMaterialExpression* Expression = MatNode->MaterialExpression;
+	FString PrimaryCategory = Expression->GetClass()->GetName();
+	TArray<FProperty*> Props = MCPUtils::SearchProperties(Expression, FString(), CPF_Edit, false);
+
+	for (FProperty* Prop : Props)
+	{
+		FString Category = Prop->HasMetaData(TEXT("Category")) ? Prop->GetMetaData(TEXT("Category")) : FString();
+		if ((Category == PrimaryCategory) == bPrimary)
+			EmitMaterialProperty(Expression, Prop, Out);
+	}
+}
+
 void FlxBlueprintExporter::EmitLocalVariables()
 {
 	for (UEdGraphNode* Node : Graph->Nodes)
@@ -312,6 +349,8 @@ void FlxBlueprintExporter::EmitDetails()
 		if (Node->IsA<UK2Node_VariableGet>()) continue;
 		Details.Appendf(TEXT("details %s\n"), *MCPUtils::FormatName(Node));
 		Details.Appendf(TEXT("  pos %d, %d\n"), Node->NodePosX, Node->NodePosY);
+
+		EmitMaterialProperties(Node, Details, false);
 	}
 }
 
@@ -327,7 +366,7 @@ void FlxBlueprintExporter::EmitComments()
 		int32 CH = CommentNode->NodeHeight;
 
 		// Emit header.
-		Output.Append(TEXT("\ncomment:\n"));
+		Output.Appendf(TEXT("\ncomment %s:\n"), *MCPUtils::FormatName(CommentNode));
 
 		// Emit wrapped, indented body.
 		Output.Append(WrapText(CommentNode->NodeComment, 70, TEXT("  - ")));

Plugins/BlueprintMCP/Source/BlueprintMCP/Private/MCPFetcher.cpp

@@ -267,6 +267,42 @@ MCPFetcher& MCPFetcher::Template()
 	return *this;
 }
 
+MCPFetcher& MCPFetcher::ToBlueprint()
+{
+	if (bError) return *this;
+	if (::Cast<UBlueprint>(Obj)) return *this;
+
+	if (UWorld* World = ::Cast<UWorld>(Obj))
+	{
+		if (!World->PersistentLevel)
+			return SetError(TEXT("ToBlueprint: World has no PersistentLevel"));
+		ULevelScriptBlueprint* LevelBP = World->PersistentLevel->GetLevelScriptBlueprint(true);
+		if (!LevelBP)
+			return SetError(TEXT("ToBlueprint: World has no level blueprint"));
+		SetObj(LevelBP);
+		return *this;
+	}
+
+	return TypeMismatch(TEXT("ToBlueprint"), TEXT("Blueprint or World"));
+}
+
+MCPFetcher& MCPFetcher::ToGraph()
+{
+	if (bError) return *this;
+	if (::Cast<UEdGraph>(Obj)) return *this;
+
+	if (UMaterial* Mat = ::Cast<UMaterial>(Obj))
+	{
+		MCPUtils::EnsureMaterialGraph(Mat);
+		if (!Mat->MaterialGraph)
+			return SetError(FString::Printf(TEXT("ToGraph: Material '%s' has no material graph"), *Mat->GetName()));
+		SetObj(Mat->MaterialGraph);
+		return *this;
+	}
+
+	return TypeMismatch(TEXT("ToGraph"), TEXT("Graph or Material"));
+}
+
 MCPFetcher& MCPFetcher::MatExp(const FString& Value)
 {
 	if (bError) return *this;

Plugins/BlueprintMCP/Source/BlueprintMCP/Public/BlueprintExporter.h

@@ -6,6 +6,8 @@
 #include "EdGraph/EdGraphNode.h"
 #include "EdGraph/EdGraphPin.h"
 
+class UMaterialExpression;
+
 class FlxBlueprintExporter
 {
 public:
@@ -60,6 +62,8 @@ private:
 	void Traverse(UEdGraphNode* Node);
 	void SortNodes();
 	void EmitNode(UEdGraphNode* Node);
+	void EmitMaterialProperty(UMaterialExpression* Expression, FProperty* Prop, FStringBuilderBase& Out);
+	void EmitMaterialProperties(UEdGraphNode* Node, FStringBuilderBase& Out, bool bPrimary);
 	void EmitLocalVariables();
 	void EmitGraph();
 	void EmitDetails();

Plugins/BlueprintMCP/Source/BlueprintMCP/Public/MCPFetcher.h

@@ -53,6 +53,10 @@ public:
 	// (e.g. Blueprint → CDO, everything else → as-is).
 	MCPFetcher& Template();
 
+	// C++-only navigation: drill down to a specific type.
+	MCPFetcher& ToBlueprint();
+	MCPFetcher& ToGraph();
+
 	// Walker table entry.
 	struct FWalker
 	{