Mechanical

ECS clearly separates the data and the logic operating on that data. This logic in turn is usually executed on an iterative per-frame basis. Apparatus implements this animation-like functionality via a concept called Mechanical. Mechanicals are complex in nature and comprise multiple Mechanics that are executed inside of them.

If you’re going the C++ way, creating your Mechanicals goes like this.

1. Open the main UE File menu and choose the “New C++ Class…” option:
2. In the opened window mark the “Show All Classes” checkbox:
3. Now you can select any of the base classes available including the Apparatus ones. Choose the Mechanical Actor as a base class:
4. Click “Next” and you should see a name choosing dialog. Adjust the name of the class as needed and proceed by pressing the green “Create Class” button at the bottom:
5. The new class gets created as a combo of its header (.h) and a source file (.cpp). All in the Source (sub)folder of your project. You should now see them in the IDE of your choice:
6. Note that you may have to recompile the project and/or restart the Editor after that. Don’t be scared by some possible errors here, regenerate the IDE project, rebuild and start again.
7. The corresponding file contents should be as:
   • MyMechanicalActor.h:

     // Fill out your copyright notice in the Description page of Project Settings.
     
     #pragma once
     
     #include "CoreMinimal.h"
     #include "MechanicalActor.h"
     #include "MyMechanicalActor.generated.h"
     
     /**
      * 
      */
     UCLASS()
     class MY_API AMyMechanicalActor : public AMechanicalActor
     {
     	GENERATED_BODY()
     	
     };
     

   • MyMechanicalActor.cpp:

     // Fill out your copyright notice in the Description page of Project Settings.
     
     
     #include "MyMechanicalActor.h"
     

8. Now you can override a single (or multiple) Tick method(s) as you usually would do in C++…
   • … in the header:

     void Tick(float DeltaTime) override;
     

   • … and the source file:

     void AMyMechanicalActor::Tick(float DeltaTime)
     {
         // Your mechanical code here...
     }
     

9. Proceed creating a Filter to enchain the Chunks/Belts in order to be iterated upon.