Files
integration/Plugins/BlueprintMCP/Source/BlueprintMCP/Private/Handlers/UMCPHandler_CreateMaterialInstanceAsset.h
2026-03-08 22:17:14 -04:00

126 lines
4.2 KiB
C++

#pragma once
#include "CoreMinimal.h"
#include "MCPHandler.h"
#include "MCPAssetFinder.h"
#include "MCPUtils.h"
#include "Materials/Material.h"
#include "Materials/MaterialInterface.h"
#include "Materials/MaterialInstanceConstant.h"
#include "Materials/MaterialExpressionScalarParameter.h"
#include "Materials/MaterialExpressionVectorParameter.h"
#include "Materials/MaterialExpressionTextureSampleParameter2D.h"
#include "Materials/MaterialExpressionStaticSwitchParameter.h"
#include "Factories/MaterialInstanceConstantFactoryNew.h"
#include "AssetToolsModule.h"
#include "IAssetTools.h"
#include "Engine/Texture.h"
#include "UMCPHandler_CreateMaterialInstanceAsset.generated.h"
// ---------------------------------------------------------------------------
// ---------------------------------------------------------------------------
// ---------------------------------------------------------------------------
UCLASS()
class UMCPHandler_CreateMaterialInstanceAsset : public UObject, public IMCPHandler
{
GENERATED_BODY()
public:
UPROPERTY(meta=(Description="Name for the new Material Instance asset"))
FString Name;
UPROPERTY(meta=(Description="Package path where the asset will be created (must start with /Game)"))
FString PackagePath;
UPROPERTY(meta=(Description="Parent material name or path (Material or Material Instance)"))
FString ParentMaterial;
virtual FString GetDescription() const override
{
return TEXT("Create a new Material Instance Constant asset with a specified parent material.");
}
virtual void Handle(const FJsonObject* Json, FJsonObject* Result) override
{
// Validate packagePath starts with /Game
if (!PackagePath.StartsWith(TEXT("/Game")))
{
return MCPUtils::MakeErrorJson(Result, TEXT("packagePath must start with '/Game'"));
}
// Check if asset already exists
{
MCPAssets<UMaterialInstanceConstant> ExistCheck;
if (!ExistCheck.Exact(Name).Errors(Result).EAny().Info()) return;
}
// Load parent material — try as Material first, then as Material Instance
UMaterialInterface* ParentMaterialObj = nullptr;
{
MCPAssets<UMaterial> MatAssets;
if (MatAssets.Exact(ParentMaterial).ETwo().Load() && !MatAssets.Objects().IsEmpty())
{
ParentMaterialObj = MatAssets.Object();
}
else
{
MCPAssets<UMaterialInstanceConstant> MIAssets;
if (MIAssets.Exact(ParentMaterial).ETwo().Load() && !MIAssets.Objects().IsEmpty())
{
ParentMaterialObj = MIAssets.Object();
}
}
}
if (!ParentMaterialObj)
{
// Also try LoadObject as a fallback with the raw path
ParentMaterialObj = LoadObject<UMaterialInterface>(nullptr, *ParentMaterial);
}
if (!ParentMaterialObj)
{
return MCPUtils::MakeErrorJson(Result, FString::Printf(
TEXT("Parent material '%s' not found. Provide a Material or Material Instance name/path."),
*ParentMaterial));
}
UE_LOG(LogTemp, Display, TEXT("BlueprintMCP: Creating Material Instance '%s' in '%s' with parent '%s'"),
*Name, *PackagePath, *ParentMaterialObj->GetName());
// Create via factory + AssetTools
IAssetTools& AssetTools = FModuleManager::LoadModuleChecked<FAssetToolsModule>("AssetTools").Get();
UMaterialInstanceConstantFactoryNew* Factory = NewObject<UMaterialInstanceConstantFactoryNew>();
UObject* NewAsset = AssetTools.CreateAsset(Name, PackagePath, UMaterialInstanceConstant::StaticClass(), Factory);
if (!NewAsset)
{
return MCPUtils::MakeErrorJson(Result, FString::Printf(TEXT("Failed to create Material Instance asset '%s' in '%s'"), *Name, *PackagePath));
}
UMaterialInstanceConstant* MI = Cast<UMaterialInstanceConstant>(NewAsset);
if (!MI)
{
return MCPUtils::MakeErrorJson(Result, TEXT("Created asset is not a UMaterialInstanceConstant"));
}
// Set parent
MI->PreEditChange(nullptr);
MI->Parent = ParentMaterialObj;
MI->PostEditChange();
// Save
bool bSaved = MCPUtils::SaveGenericPackage(MI);
UE_LOG(LogTemp, Display, TEXT("BlueprintMCP: Created Material Instance '%s' with parent '%s' (saved: %s)"),
*Name, *ParentMaterialObj->GetName(), bSaved ? TEXT("true") : TEXT("false"));
Result->SetStringField(TEXT("path"), MI->GetPathName());
Result->SetStringField(TEXT("parent"), ParentMaterialObj->GetPathName());
Result->SetBoolField(TEXT("saved"), bSaved);
}
};