Optimization with Profiler, Frame Debugger, and Memory Profiler

Welcome to the fourth part of this book—I am glad you have reached this part as it means that you have almost completed a full game! In this chapter, we are going to discuss optimization techniques to review your game’s performance and improve it, as having a good and constant framerate is vital to any game.

Performance is a broad topic that requires a deep understanding of several Unity systems and could span several books. We are going to look at how to measure performance and explore the effects of our changes to systems to learn how they work through testing.

In this chapter, we will examine the following performance concepts:

• Optimizing graphics
• Optimizing processing
• Optimizing memory

By the end of this chapter, you will be able to gather performance data of the three main pieces of hardware that run your game—the GPU, CPU, and RAM. You will be able to...

Optimizing graphics

The most common cause of performance issues is related to the misuse of assets, especially on the graphics side, due to not having enough knowledge of how Unity’s graphics engines work. We are going to explore how a GPU works at a high level and how to improve its usage.

In this section, we will examine the following graphics optimization concepts:

• Introduction to graphics engines
• Using Frame Debugger
• Using batching
• Other optimizations

We will start by looking at a high-level overview of how graphics are rendered to better understand the performance data that we will gather later in Frame Debugger. Based on the debugger’s results, we are going to identify the areas where we can apply batching (which is a technique to combine the rendering process of several objects, reducing its cost), along with other common optimizations to keep in mind.

Introduction to graphics engines

Nowadays, every gaming device...

Optimizing processing

While graphics usually take up most of the time that a frame needs to be generated, we should never underestimate the cost of badly optimized code and scenes. There are several parts of the game that are still calculated in the CPU, including part of the graphics process (such as the batching calculations), physics, audio, and our code. Here, we have a lot more causes of performance issues than on the graphics side, so again, instead of discussing every optimization, let’s learn how to discover them.

In this section, we will examine the following CPU optimization concepts:

• Detecting CPU- and GPU-bound
• Using the CPU Usage Profiler
• General CPU optimization techniques

We will start by discussing the concepts of CPU- and GPU-bound, which focus on the optimization process, determining whether the problem is GPU- or CPU-related. Later, as with the GPU optimization process, we will look at how to gather the performance data...

Optimizing memory

We discussed how to profile and optimize two pieces of hardware—the CPU and GPU—but there is another piece of hardware that plays a key role in our game—RAM. This is the place where we put all of our game’s data. Games can be memory-intensive applications, and unlike several other applications, they are constantly executing code, so we need to be especially careful about that.

In this section, we will examine the following memory optimization concepts:

• Memory allocation and the garbage collector
• Using the Memory Profiler

Let’s start discussing how memory allocation works and what role garbage collection plays here.

Memory allocation and the garbage collector

Each time we instantiate an object, we are allocating memory in RAM, and in a game, we will be allocating memory constantly. In other programming languages, aside from allocating the memory, you need to manually deallocate it, but C# has...

Summary

Optimizing a game is not an easy task, especially if you are not familiar with the internals of how each Unity system works. Sadly, this is a titanic task, and no one knows every single system down to its finest details, but with the tools learned in this chapter, we have a way to explore how changes affect systems through exploration. We learned how to profile the CPU, GPU, and RAM and what the key hardware in any game is, as well as covered some common good practices to avoid abusing them.

Now, you are able to diagnose performance issues in your game, gathering data about the performance of the three main pieces of hardware—the CPU, GPU, and RAM—and then using that data to focus your optimization efforts on applying the correct optimization technique. Performance is important as your game needs to run smoothly to give your users a pleasant experience.

In the next chapter, we are going to see how to create a build of our game to share with other people...