Creating Editor Visualization for Move Component in Unreal Engine 5 C++

Previous Video Recap

• Topics Covered: Move component, actors, and components
• Move Component: Moved an object around the scene with an FVector move offset (3D vector) and a speed parameter to control movement.
• Drawbacks: No visualization of where the object was moving, making it frustrating to set up correctly.

Today's Objective

• Goal: Add editor visualization for the move component using Unreal Engine's editor modules and interfaces.
• Steps: Understanding Unreal Engine core concepts and modules, followed by creating and registering the editor module.

Core Concepts of Unreal Engine

• Modules: Containers with headers and source code serving specific purposes (engine, editor, game, plugins).
• Example (Visual Studio structure):
  • Runtime directory (contains modules like D3D12RHI for DirectX 12).
  • Source directory (contains the project-specific modules like newCPPTutorial).

Creating an Editor Module

Step 1: Modify Project File

• Project File: Add a new module entry in the .uproject file. { "Name": "newCPPTutorialEditor", "Type": "Editor", "LoadingPhase": "PostEngineInit" }
• Reason: Separate game code from editor-specific code for clear distinction and shipping purposes.

Step 2: Modify Target File

• Target File: Add the new module in newCPPTutorialEditor.Target.cs. ExtraModuleNames.AddRange(new string[] { "newCPPTutorial", "newCPPTutorialEditor" });
• Create Module Folder: In Source directory, add newCPPTutorialEditor folder and create necessary files (.Build.cs, source files).

Step 3: Implementing Editor Module

Editor Module Header (.h file)

• Create File: newCPPTutorialEditor.h class FNewCPPTutorialEditorModule : public IModuleInterface { public: virtual void StartupModule() override; virtual void ShutdownModule() override; };

Editor Module Source (.cpp file)

• Create File: newCPPTutorialEditor.cpp #include "newCPPTutorialEditor.h" IMPLEMENT_MODULE(FNewCPPTutorialEditorModule, newCPPTutorialEditor)
• Build File: Add dependencies. PublicDependencyModuleNames.AddRange(new string[] { "newCPPTutorial", "UnrealEd" });

Step 4: Register Component Visualizer

• Create Visualizer Files: newCPPTutorialEditor/MoveComponentVisualizer.h and .cpp class FMoveComponentVisualizer : public FComponentVisualizer { // Define methods here }
• Register Visualizer in StartupModule void FNewCPPTutorialEditorModule::StartupModule() { if (GUnrealEd) { TSharedPtr<FMoveComponentVisualizer> Visualizer = MakeShareable(new FMoveComponentVisualizer); GUnrealEd->RegisterComponentVisualizer(UMoveComponent::StaticClass()->GetFName(), Visualizer); Visualizer->OnRegister(); } }
• Unregister in ShutdownModule void FNewCPPTutorialEditorModule::ShutdownModule() { if (GUnrealEd) { GUnrealEd->UnregisterComponentVisualizer(UMoveComponent::StaticClass()->GetFName()); } }

Implementing Draw Visualization Function

• Header File: MoveComponentVisualizer.h virtual void DrawVisualization(const UActorComponent* Component, const FSceneView* View, FPrimitiveDrawInterface* PDI) override;
• Source File: MoveComponentVisualizer.cpp void FMoveComponentVisualizer::DrawVisualization(const UActorComponent* Component, const FSceneView*, FPrimitiveDrawInterface* PDI) { // Implement draw logic }
• Draw Line Example: PDI->DrawLine(StartVector, EndVector, FLinearColor::Red, SDPG_World);

Final Steps

• Build and Test: Ensure Unreal Engine compiles successfully and the editor visualizations appear as intended.
• Debugging: Use the Module panel in Unreal Engine to check if modules load correctly.

Conclusion

• Outcome: Successfully added in-editor visualization for Move Component.
• Next Steps: Improve move functionality, allowing interactions with Blueprints, dynamic pausing, and resetting movements.

Stay tuned for more tutorials!