カテゴリー: AI

投稿日:

[UE5.7][C++]自宅AI(Ollama)サーバーをUE5のC++プラグインで連携したよ


まず全体全体（おすすめ）

A.別途REST（非ストリーミング）で完了させる

  • UE → AIサーバへHTTP POST
  • AI → 問題JSON
  • UE → UIに反映（UMG）

メリット：実装が簡単／デバッグしやすいプレイ
：とにかくが長いと立つが出る

自宅AI側：エンドポイントの考え方

あなたが今 OpenWebUI を使っているなら、内部のモデル実体はおそらくOllama。

  • Ollamaの代表的なAPI（例）
    • 生成：POST /api/generate
    • チャット：POST /api/chat

UEからは「どのURLに投げるか」だけ差し替えできるようにしておくのが正解。

UE5プラグイン設計（ほぼこれを入れる）

1) 設定（プロジェクトの設定を出す）

  • ベースURL（例：http://192.168.1.23:11434）
  • モデル名（例：llama3.1）
  • タイムアウト秒
  • オプション: API Key（OpenAI互換を使う場合）

UDeveloperSettingsを使うと綺麗。

実装：UE5 C++（RESTで会話させる最小セット）

(1) ビルド.cs

  • "HTTP"、、"Json"を"JsonUtilities"追加

(2) 送信受信用の構造体（JSON）

  • リクエスト: モデル / プロンプト（またはメッセージ）
  • 応答: 応答（または選択肢）

(3) ブループリント非同期ノード化（UIに優しい）

  • UBlueprintAsyncActionBaseで
    • OnSuccess
    • OnError
      を吐く

作った全コード

furcraHomeAIServerChat2.Build.cs

// Some copyright should be here...

using UnrealBuildTool;

public class furcraHomeAIServerChat2 : ModuleRules
{
	public furcraHomeAIServerChat2(ReadOnlyTargetRules Target) : base(Target)
	{
		PCHUsage = ModuleRules.PCHUsageMode.UseExplicitOrSharedPCHs;
		
		PublicIncludePaths.AddRange(
			new string[] {
				// ... add public include paths required here ...
			}
			);
			
		
		PrivateIncludePaths.AddRange(
			new string[] {
				// ... add other private include paths required here ...
			}
			);
			
		
		PublicDependencyModuleNames.AddRange(
			new string[]
			{
                "Core", "CoreUObject", "Engine", "UMG","HTTP", "Json", "JsonUtilities"
				// ... add other public dependencies that you statically link with here ...
			}
			);
			
		
		PrivateDependencyModuleNames.AddRange(
			new string[]
			{
				"CoreUObject",
				"Engine",
				"Slate",
				"SlateCore",
				"DeveloperSettings",
				// ... add private dependencies that you statically link with here ...	
			}
			);
		
		
		DynamicallyLoadedModuleNames.AddRange(
			new string[]
			{
				// ... add any modules that your module loads dynamically here ...
			}
			);
	}
}

AiChatTypes.h

// Fill out your copyright notice in the Description page of Project Settings.

#pragma once

#include "CoreMinimal.h"

/**
 * 
 */
class FURCRAHOMEAISERVERCHAT2_API AiChatTypes
{
public:
	AiChatTypes();
	~AiChatTypes();
};





#include "AiChatTypes.generated.h"

USTRUCT(BlueprintType)
struct FAiChatMessage
{
	GENERATED_BODY()

	// "system" | "user" | "assistant"
	UPROPERTY(BlueprintReadWrite, EditAnywhere) FString role;
	UPROPERTY(BlueprintReadWrite, EditAnywhere) FString content;
};

USTRUCT()
struct FOllamaChatRequest
{
	GENERATED_BODY()

	UPROPERTY() FString model;
	UPROPERTY() TArray<FAiChatMessage> messages;
	UPROPERTY() bool stream = false;
};

USTRUCT()
struct FOllamaChatMessage
{
	GENERATED_BODY()

	UPROPERTY() FString role;
	UPROPERTY() FString content;
};

USTRUCT()
struct FOllamaChatResponse
{
	GENERATED_BODY()

	UPROPERTY() FOllamaChatMessage message;
	UPROPERTY() bool done = false;
};

AiChatTypes.cpp

// Fill out your copyright notice in the Description page of Project Settings.


#include "AiChatTypes.h"

AiChatTypes::AiChatTypes()
{
}

AiChatTypes::~AiChatTypes()
{
}

AiLinkAsyncChat.h

// Fill out your copyright notice in the Description page of Project Settings.

#pragma once

#include "CoreMinimal.h"
#include "Kismet/BlueprintAsyncActionBase.h"
#include "AiChatTypes.h"
#include "AiLinkAsyncChat.generated.h"

// Forward declarations for HTTP interfaces to avoid including HTTP headers in this public header
class IHttpRequest;
class IHttpResponse;

using FHttpRequestPtr = TSharedPtr<IHttpRequest, ESPMode::ThreadSafe>;
using FHttpResponsePtr = TSharedPtr<IHttpResponse, ESPMode::ThreadSafe>;

DECLARE_DYNAMIC_MULTICAST_DELEGATE_OneParam(FAiChatSuccess, const FString&, AssistantText);
DECLARE_DYNAMIC_MULTICAST_DELEGATE_OneParam(FAiChatError, const FString&, Error);

UCLASS()
class FURCRAHOMEAISERVERCHAT2_API UAiLinkAsyncChat : public UBlueprintAsyncActionBase
{
	GENERATED_BODY()
public:
	UPROPERTY(BlueprintAssignable) FAiChatSuccess OnSuccess;
	UPROPERTY(BlueprintAssignable) FAiChatError OnError;

	// Messagesは「system + 履歴 + 今回のuser」を含めて渡す
	UFUNCTION(BlueprintCallable, meta = (BlueprintInternalUseOnly = "true"))
	static UAiLinkAsyncChat* SendChat(const TArray<FAiChatMessage>& Messages);

	virtual void Activate() override;

private:
	TArray<FAiChatMessage> MessagesInternal;
	void HandleResponse(FHttpRequestPtr Req, FHttpResponsePtr Resp, bool bOk);
};

AiLinkAsyncChat.cpp

// Fill out your copyright notice in the Description page of Project Settings.


#include "AiLinkAsyncChat.h"

#include "UAiLinkSettings.h"
#include "HttpModule.h"
#include "Interfaces/IHttpRequest.h"
#include "Interfaces/IHttpResponse.h"
#include "JsonObjectConverter.h"

UAiLinkAsyncChat* UAiLinkAsyncChat::SendChat(const TArray<FAiChatMessage>& Messages)
{
	auto* Node = NewObject<UAiLinkAsyncChat>();
	Node->MessagesInternal = Messages;
	return Node;
}

void UAiLinkAsyncChat::Activate()
{
	const UAiLinkSettings* S = GetDefault<UAiLinkSettings>();
	if (!S)
	{
		OnError.Broadcast(TEXT("Settings not found"));
		return;
	}

	const FString Url = S->BaseUrl / TEXT("api/chat");

	FOllamaChatRequest Body;
	Body.model = S->Model;
	Body.messages = MessagesInternal;
	Body.stream = false;

	FString JsonStr;
	if (!FJsonObjectConverter::UStructToJsonObjectString(Body, JsonStr))
	{
		OnError.Broadcast(TEXT("Failed to serialize request JSON"));
		return;
	}

	TSharedRef<IHttpRequest, ESPMode::ThreadSafe> Req = FHttpModule::Get().CreateRequest();
	Req->SetURL(Url);
	Req->SetVerb(TEXT("POST"));
	Req->SetHeader(TEXT("Content-Type"), TEXT("application/json; charset=utf-8"));
	Req->SetTimeout(S->TimeoutSeconds);
	Req->SetContentAsString(JsonStr);

	Req->OnProcessRequestComplete().BindUObject(this, &UAiLinkAsyncChat::HandleResponse);
	Req->ProcessRequest();

	UE_LOG(LogTemp, Warning, TEXT("[AI] Activate() called"));
	UE_LOG(LogTemp, Warning, TEXT("[AI] URL: %s"), *Req->GetURL());
	UE_LOG(LogTemp, Warning, TEXT("[AI] Payload: %s"), *JsonStr);
}

void UAiLinkAsyncChat::HandleResponse(FHttpRequestPtr Req, FHttpResponsePtr Resp, bool bOk)
{
	if (!bOk || !Resp.IsValid())
	{
		OnError.Broadcast(TEXT("HTTP request failed (no response)"));
		return;
	}

	const int32 Code = Resp->GetResponseCode();
	const FString Content = Resp->GetContentAsString();
	UE_LOG(LogTemp, Warning, TEXT("[AI] HTTP %d"), Code);
	UE_LOG(LogTemp, Warning, TEXT("[AI] Body: %s"), *Content);

	UE_LOG(LogTemp, Warning, TEXT("[AI] HandleResponse() called. bOk=%d RespValid=%d"),
		bOk ? 1 : 0, Resp.IsValid() ? 1 : 0);

	if (Resp.IsValid())
	{
		UE_LOG(LogTemp, Warning, TEXT("[AI] HTTP %d"), Resp->GetResponseCode());
		UE_LOG(LogTemp, Warning, TEXT("[AI] Body: %s"), *Resp->GetContentAsString());
	}



	if (Code < 200 || Code >= 300)
	{
		OnError.Broadcast(FString::Printf(TEXT("HTTP %d: %s"), Code, *Content));
		return;
	}

	FOllamaChatResponse Parsed;
	if (!FJsonObjectConverter::JsonObjectStringToUStruct(Content, &Parsed, 0, 0))
	{
		OnError.Broadcast(FString::Printf(TEXT("Failed to parse JSON: %s"), *Content));
		return;
	}

	UE_LOG(LogTemp, Warning, TEXT("[AI] Broadcasting Success: %s"), *Parsed.message.content);
	OnSuccess.Broadcast(Parsed.message.content);

}

AiLinkAsyncGenerate.h

// Fill out your copyright notice in the Description page of Project Settings.

#pragma once

#include "CoreMinimal.h"
#include "Kismet/BlueprintAsyncActionBase.h"
#include "AiLinkRequestTypes.h"
#include "AiLinkAsyncGenerate.generated.h"

// Forward declarations for HTTP interfaces to avoid including HTTP headers in this public header
class IHttpRequest;
class IHttpResponse;

using FHttpRequestPtr = TSharedPtr<IHttpRequest, ESPMode::ThreadSafe>;
using FHttpResponsePtr = TSharedPtr<IHttpResponse, ESPMode::ThreadSafe>;

DECLARE_DYNAMIC_MULTICAST_DELEGATE_OneParam(FAiGenerateSuccess, const FString&, Text);
DECLARE_DYNAMIC_MULTICAST_DELEGATE_OneParam(FAiGenerateError, const FString&, Error);

UCLASS()
class FURCRAHOMEAISERVERCHAT2_API UAiLinkAsyncGenerate : public UBlueprintAsyncActionBase
{
	GENERATED_BODY()
public:
	UPROPERTY(BlueprintAssignable) FAiGenerateSuccess OnSuccess;
	UPROPERTY(BlueprintAssignable) FAiGenerateError OnError;

	UFUNCTION(BlueprintCallable, meta = (BlueprintInternalUseOnly = "true"))
	static UAiLinkAsyncGenerate* GenerateText(const FString& Prompt);

	virtual void Activate() override;

private:
	FString PromptInternal;
	void HandleResponse(FHttpRequestPtr Req, FHttpResponsePtr Resp, bool bOk);
};

AiLinkAsyncGenerate.cpp

// Fill out your copyright notice in the Description page of Project Settings.


#include "AiLinkAsyncGenerate.h"

#include "UAiLinkSettings.h"	
#include "HttpModule.h"
#include "Interfaces/IHttpRequest.h"
#include "Interfaces/IHttpResponse.h"
#include "JsonObjectConverter.h"

UAiLinkAsyncGenerate* UAiLinkAsyncGenerate::GenerateText(const FString& Prompt)
{
	auto* Node = NewObject<UAiLinkAsyncGenerate>();
	Node->PromptInternal = Prompt;
	return Node;
}

void UAiLinkAsyncGenerate::Activate()
{
	const UAiLinkSettings* S = GetDefault<UAiLinkSettings>();
	if (!S)
	{
		OnError.Broadcast(TEXT("Settings not found"));
		return;
	}

	const FString Url = S->BaseUrl / TEXT("api/generate");

	FOllamaGenerateRequest Body;
	Body.model = S->Model;
	Body.prompt = PromptInternal;
	Body.stream = false;

	FString JsonStr;
	if (!FJsonObjectConverter::UStructToJsonObjectString(Body, JsonStr))
	{
		OnError.Broadcast(TEXT("Failed to serialize request JSON"));
		return;
	}

	TSharedRef<IHttpRequest, ESPMode::ThreadSafe> Req = FHttpModule::Get().CreateRequest();
	Req->SetURL(Url);
	Req->SetVerb(TEXT("POST"));
	Req->SetHeader(TEXT("Content-Type"), TEXT("application/json; charset=utf-8"));
	Req->SetTimeout(S->TimeoutSeconds);
	Req->SetContentAsString(JsonStr);

	Req->OnProcessRequestComplete().BindUObject(this, &UAiLinkAsyncGenerate::HandleResponse);
	Req->ProcessRequest();
}

void UAiLinkAsyncGenerate::HandleResponse(FHttpRequestPtr Req, FHttpResponsePtr Resp, bool bOk)
{
	if (!bOk || !Resp.IsValid())
	{
		OnError.Broadcast(TEXT("HTTP request failed (no response)"));
		return;
	}

	const int32 Code = Resp->GetResponseCode();
	const FString Content = Resp->GetContentAsString();

	if (Code < 200 || Code >= 300)
	{
		OnError.Broadcast(FString::Printf(TEXT("HTTP %d: %s"), Code, *Content));
		return;
	}

	FOllamaGenerateResponse Parsed;
	if (!FJsonObjectConverter::JsonObjectStringToUStruct(Content, &Parsed, 0, 0))
	{
		OnError.Broadcast(FString::Printf(TEXT("Failed to parse JSON: %s"), *Content));
		return;
	}

	OnSuccess.Broadcast(Parsed.response);
}

AiLinkRequestTypes.h

// Fill out your copyright notice in the Description page of Project Settings.

#pragma once

#include "CoreMinimal.h"

/**
 * 
 */
class FURCRAHOMEAISERVERCHAT2_API AiLinkRequestTypes
{
public:
	AiLinkRequestTypes();
	~AiLinkRequestTypes();
};


//#pragma once
//#include "CoreMinimal.h"
#include "AiLinkRequestTypes.generated.h"

USTRUCT()
struct FOllamaGenerateRequest
{
	GENERATED_BODY()

	UPROPERTY() FString model;
	UPROPERTY() FString prompt;
	UPROPERTY() bool stream = false;
};

USTRUCT()
struct FOllamaGenerateResponse
{
	GENERATED_BODY()

	UPROPERTY() FString response;
	UPROPERTY() bool done = false;
};

AiLinkRequestTypes.cpp

// Fill out your copyright notice in the Description page of Project Settings.


#include "AiLinkRequestTypes.h"

AiLinkRequestTypes::AiLinkRequestTypes()
{
}

AiLinkRequestTypes::~AiLinkRequestTypes()
{
}

UAiLinkSettings.h

// Fill out your copyright notice in the Description page of Project Settings.

#pragma once

#include "CoreMinimal.h"
#include "Engine/DeveloperSettings.h"
#include "UAiLinkSettings.generated.h"

UCLASS(Config = Game, DefaultConfig, meta = (DisplayName = "Home AI Chat"))
class FURCRAHOMEAISERVERCHAT2_API UAiLinkSettings : public UDeveloperSettings
{
	GENERATED_BODY()

public:
	UPROPERTY(Config, EditAnywhere, Category = "AI")
	FString BaseUrl = TEXT("http://192.168.1.23:11434");

	UPROPERTY(Config, EditAnywhere, Category = "AI")
	//FString Model = TEXT("llama3.1"); 
	//FString Model = TEXT("deepseek-r1:32b");llama3.1:8b
	//FString Model = TEXT("llama3.1:70b");//llama3.1:8b
	FString Model = TEXT("llama3.1:8b");//
	UPROPERTY(Config, EditAnywhere, Category = "AI")
	float TimeoutSeconds = 120.0f;

	// 例: "You are NPC assistant in my game..."
	UPROPERTY(Config, EditAnywhere, Category = "AI")
	FString SystemPrompt = TEXT("You are a helpful in-game NPC. Keep replies concise.");
};

UAiLinkSettings.cpp

// Fill out your copyright notice in the Description page of Project Settings.


#include "UAiLinkSettings.h"

BluePrintはこんなかんじ

以上。

投稿日:

[UE5.7][VisualStudio][Cpp]UnrealEngineのCPPプラグインからOpenAI(ChatGPT4o)を呼んでみるのできた。2025/12/15再更新

プラグインの作り方はこの記事から

https://furcraea.verse.jp/wp/2024/09/28/ue5-3-how-to-create-a-cpp-plugin

furcraeaUEOpenAI　ってプラグイン作って

D:\Sandbox\UE53CratePlugin\UE53CreatePlugin\Plugins\furcraeaUEOpenAI\Source\furcraeaUEOpenAI\furcraeaUEOpenAI.Build.cs のPublicDependencyModuleNamesに

“HTTP”, “Json”,

を追加

furcraeaUEOpenAI.Build.cs 

// Some copyright should be here...

using UnrealBuildTool;

public class furcraeaUEOpenAI : ModuleRules
{
	public furcraeaUEOpenAI(ReadOnlyTargetRules Target) : base(Target)
	{
		PCHUsage = ModuleRules.PCHUsageMode.UseExplicitOrSharedPCHs;
		
		PublicIncludePaths.AddRange(
			new string[] {
				// ... add public include paths required here ...
			}
			);
				
		
		PrivateIncludePaths.AddRange(
			new string[] {
				// ... add other private include paths required here ...
			}
			);
			
		
		PublicDependencyModuleNames.AddRange(
			new string[]
			{
				"Core","HTTP", "Json", 
				// ... add other public dependencies that you statically link with here ...
			}
			);
			
		
		PrivateDependencyModuleNames.AddRange(
			new string[]
			{
				"CoreUObject",
				"Engine",
				"Slate",
				"SlateCore",
				// ... add private dependencies that you statically link with here ...	
			}
			);
		
		
		DynamicallyLoadedModuleNames.AddRange(
			new string[]
			{
				// ... add any modules that your module loads dynamically here ...
			}
			);
	}
}

furcraeaOpenAILib2BPLibrary.h

// Copyright Epic Games, Inc. All Rights Reserved.

#pragma once

#include "Kismet/BlueprintFunctionLibrary.h"
#include "furcraeaOpenAILib2BPLibrary.generated.h"

/* 
*	Function library class.
*	Each function in it is expected to be static and represents blueprint node that can be called in any blueprint.
*
*	When declaring function you can define metadata for the node. Key function specifiers will be BlueprintPure and BlueprintCallable.
*	BlueprintPure - means the function does not affect the owning object in any way and thus creates a node without Exec pins.
*	BlueprintCallable - makes a function which can be executed in Blueprints - Thus it has Exec pins.
*	DisplayName - full name of the node, shown when you mouse over the node and in the blueprint drop down menu.
*				Its lets you name the node using characters not allowed in C++ function names.
*	CompactNodeTitle - the word(s) that appear on the node.
*	Keywords -	the list of keywords that helps you to find node when you search for it using Blueprint drop-down menu. 
*				Good example is "Print String" node which you can find also by using keyword "log".
*	Category -	the category your node will be under in the Blueprint drop-down menu.
*
*	For more info on custom blueprint nodes visit documentation:
*	https://wiki.unrealengine.com/Custom_Blueprint_Node_Creation
*/
UCLASS()
class UfurcraeaOpenAILib2BPLibrary : public UBlueprintFunctionLibrary
{
	GENERATED_UCLASS_BODY()

public:
	UFUNCTION(BlueprintCallable, meta = (DisplayName = "Sample Function", Keywords = "furcraeaOpenAILib2 sample"), Category = "furcraeaOpenAILib2")
	static float furcraeaOpenAILib2SampleFunction(float Param);

	UFUNCTION(BlueprintCallable, meta = (DisplayName = "Curl Send Request 4", Keywords = "furcraeaOpenAILib2 curl http request openai"), Category = "furcraeaOpenAILib2")
	static void CurlSendRequest4();
};

furcraeaOpenAILib2BPLibrary.cpp

// Copyright Epic Games, Inc. All Rights Reserved.

#include "furcraeaOpenAILib2BPLibrary.h"
#include "furcraeaOpenAILib2.h"
#include "HttpModule.h"
#include "Interfaces/IHttpRequest.h"
#include "Interfaces/IHttpResponse.h"

UfurcraeaOpenAILib2BPLibrary::UfurcraeaOpenAILib2BPLibrary(const FObjectInitializer& ObjectInitializer)
: Super(ObjectInitializer)
{

}

float UfurcraeaOpenAILib2BPLibrary::furcraeaOpenAILib2SampleFunction(float Param)
{
	return -1;
}


void UfurcraeaOpenAILib2BPLibrary::CurlSendRequest4()
{
	FString ApiKey = TEXT("sk-からはじまるKEY");

	TSharedRef<IHttpRequest, ESPMode::ThreadSafe> HttpRequest = FHttpModule::Get().CreateRequest();
	HttpRequest->SetURL("https://api.openai.com/v1/chat/completions");

	HttpRequest->SetVerb("POST");
	HttpRequest->SetHeader("Content-Type", "application/json");
	HttpRequest->SetHeader("Authorization", "Bearer " + ApiKey);

	// JSON Body
	FString Content = TEXT(R"(
    {
        "model": "gpt-4o-mini",
        "messages": [{"role": "user", "content": "Say this is a test!"}],
        "temperature": 0.7
    }
    )");

	HttpRequest->SetContentAsString(Content);
	//
	HttpRequest->OnProcessRequestComplete().BindLambda([](FHttpRequestPtr Request, FHttpResponsePtr Response, bool bWasSuccessful)
		{
			if (bWasSuccessful && Response.IsValid())
			{
				FString ResponseContent = Response->GetContentAsString();
				UE_LOG(LogTemp, Warning, TEXT("%s"), *ResponseContent);
			}
			else
			{
				UE_LOG(LogTemp, Error, TEXT("Request failed"));
			}
		});
	HttpRequest->ProcessRequest();
}

VSでbuild.

新規ブループリントから　Widget BluePrint >User Widgetで作成　WBP_ApiTest

ボタン配置

ボタンに下記ノード作成

新規ブループリントから　GameModeBase　の 　名前　AI_Button_GameModeで作成した

Create WBP からWBP Api Testを選びAdd Viewport

GameMode OverrideにAI_Button_GameMode選ぶ

で再生

作ったボタンおしてみると！応答が返ってきた！！