Unreal C++ Course - Update #5 - From Text-based to 3D! (Don't talk to me about pointers)

 Did I mention I'm trying to learn about pointers...

Theory over practical

The instructor is really glossing over the technical aspects, so of the 12 tasks completed since last post, most are related to the UE Editor / AActor class. However, I am anxious to ensure I don't just learn how to create the 5 projects they show us how to create, but can also apply what I have learned to my own project. I am not struggling for ideas, just the tool-set to materialise them.

Pointers, so far, do look  very powerful and simple to use. They also look really simple to destroy the (virtual) world with. The game concept I have in mind will have many entities, each with a lot of properties, so performance will be a factor. Not constantly crashing or random values changing unexpectedly are also factors. The point is (I'm sorry) I need to know how to use them.

My learning process

Thanks to comments on this blog (I knew it would be useful somehow!), I have a better understanding of pointers in theory. Actually, I have multiple levels of floundering that are helping me to grasp this stuff:

1. Watch the lectures, sometimes many times.
2. Document my level of understanding in the notes section to a brutally honest degree (making sure to also vent at the lecturer).
3. Google things I think (hope) can be cleared up by reading a little. So far, this has a low success rate as it is like getting sucked into a gravity (information) well. I think helpful context is gradually building up, though.
4. Complete the exercises. So far this has been almost self-explanatory, but with the exercise below we had to work out which functions to use ourselves by using the Unreal Engine documentation. Admittedly, I guessed it with the help of IntelliSense, but I understand how to read the docs a little more now.
   I do like when they set us a "challenge" and we have to use what we know, but the degree of abstraction has been so tiny thus far, so I am not leaning on it to assure me I grasped the underlying concept.
5. Write up a summary of what I learned right here, on this blog. This is great for writing to long term memory. Also, because of my need to hold myself accountable to others, it means I won't try to overstate my understanding of something. This makes it easier to keep track of what I can take for granted, and what requires prioritisation for further development of my understanding.
6. Learning when to move on. I must give credit to the course developers: so far, some clarification on topics touched on earlier has been provided. So as the course progresses, I am starting to become wary of obsessing too much over achieving a full understanding right now.

The knowledge:practice ratio

The trouble is, I am still struggling to have confidence in my understanding of how pointers work in the code we are writing in the course. For example:

FString ObjectPosition = GetOwner()->GetActorLocation().ToString();

If I am understanding correctly,  GetOwner() returns an AActor pointer that we need to access with ->. It does this because there is no point (that just slipped out) creating effectively another copy of the class when we do not intend to modify it, so we can just reference it directly.

We then pass in the value at the pointer to GetActorLocation(). This does not return a pointer, so we can just use the dot operator ToString().

Provided I have not misunderstood, so far so good. However, I still have so many questions about when to create and use them myself. And I am still struggling to understand the difference between a pointer and an address-of-operator.

I think:

• *ptr = The value at an address.
• &ptr = The address itself.
• ptr = Failure. If it started life as a pointer, referring to it like this will fail.

Looking ahead... a little

If I am wrong, it's not a major issue at the moment. It isn't blocking the completion of the next steps. I will pick it up eventually!

Speaking of, the next few lectures look to be focused on designing the level. The focus of the blog isn't really on replicating other's art in an editor I'm familiar with, so unless I learn any interesting editor tips, I may skip covering it here so I can focus on documenting the learning process.