C++ Unreal Tutorial Problems

Nitr0o · January 23, 2018, 3:26am

So, I am trying to learn how to program with UE4, coming from Unity and online videos seem like a mess to me but the documentation online helps a lot. However… after attempting to follow along the tutorials I found myself with a problem…

In one of the tutorials (Creating and Attaching Components) it says to write in
USphereComponent* SphereComponent = CreateDefaultSubobject<USphereComponent>(TEXT(“RootComponent”)); However the USphereComponent part at the beginning is giving me errors. Do I need to include a library or something?

Jnat · January 23, 2018, 6:33am

Hi !
The error you obtain is needed to help you.
If you can include your code too it would be very useful.

Where are you puting your function ?

jnat

FSapio · January 23, 2018, 12:09pm

Yes, you need to include a reference to the Sphere Component. The tutorial you are watching may be outdated, since, some versions ago the dependencies have been reduced, so to minimize compilation time. As a result, you will need to include the headers that you need.

In your specific case, you need to add the following include:


#include "Components/SphereComponent.h"

For further reference to where you can find the header to include, have a look to the documentation of the class you intend to use. In your case, visit the official documentation for USphereComponent and you can find the header at the bottom of the page. Alternatively, you can search the class within the engine code, and once found it, you can include the header.

darkgaze · January 23, 2018, 4:44pm

This is something I found last months learning too:

CreateDefaultSubobject can ONLY be put inside the construction or contructor methods. You need to build those just inside that method

Nitr0o · January 23, 2018, 11:28pm

FSapio:

Yes, you need to include a reference to the Sphere Component. The tutorial you are watching may be outdated, since, some versions ago the dependencies have been reduced, so to minimize compilation time. As a result, you will need to include the headers that you need.

In your specific case, you need to add the following include:
#include "Components/SphereComponent.h"
For further reference to where you can find the header to include, have a look to the documentation of the class you intend to use. In your case, visit the official documentation for USphereComponent and you can find the header at the bottom of the page. Alternatively, you can search the class within the engine code, and once found it, you can include the header.

Thanks that worked! Guess I would just have to go look for headers whenever I use components then!

FSapio · January 24, 2018, 10:30am

You are welcome. It might be tedious at the beginning to include all the headers you need, and in general getting used to C++ in Unreal. However, once you have master it, you will appreciate the full power that it unlocks.