Creating Optimized Game Art for VR in UE4

Server 17 has come a long way. We have brought the game from a simple puzzle idea to a working game prototype. At this stage, we have a sample level, custom gameplay, and custom interfaces. We have built interaction systems that can be expanded to add even more game mechanics. However, the game is not much to look at, is it? Our lighting is basic. We are still using the default textures for many things. There is nothing wrong with it, since this is still a game prototype, but if we want to be able to present this to anyone beyond family and friends, it is going to need a bit of sprucing up.

Creating 3D game art for VR is not like creating game art for other titles. Though we use many of the same programs, VR requires us to be conservative with our art. The performance requirements of VR demand that we keep polygon counts low, use tricks...

Performance is key

Again and again, we have touched on the theme of performance in VR. We talked about it first when we discussed VR sickness in Chapter 1, Introducing VR Technology in Unreal Engine 4. We touched on it again in Chapter 3, Exploring Riveting Gameplay in Virtual Reality, when we programmed the interaction systems that make our game work. So, why do we keep talking about it? Performance is central to enjoying a VR experience. Having high-end visuals helps our players become immersed in our digital environments, while keeping steady frame rates is the best way to maximize player comfort and reduce VR sickness. So, how do we balance both of these needs?

In this chapter, we are going to talk about performance regarding to 3D game art, lighting, and visual effects. In VR, managing your assets and detail level becomes a balancing act. How do we provide the visuals required...

Artistic limitations in VR

Now that we have a basic understanding, it's time to get specific. How do the limitations we face in VR affect each of the following categories of game art?:

• Static and skeletal meshes
• Materials
• Lighting
• Visual effects

Each category represents different limitations that need to be considered when creating the visuals for our game.

Static and skeletal mesh limitations

Let's start by taking a look at static and skeletal meshes:

The static mesh editor in Unreal 4

Static and skeletal meshes represent the majority of the art that goes into creating a game in Unreal Engine 4. These are your 3D models and tend to be sorted into groups such as environment, character, weapon, vehicle, and so...

Performance-boosting techniques

With the player's comfort to consider and all of these limitations, how are designers creating amazing 3D worlds for VR users to step into? The answer can be summed up in the phase fake it till you make it. The technology behind VR is rapidly evolving. New techniques for dealing with the issues we've mentioned are being built into the next generation of game engines. However, for now, there are some best practices currently being used by artists in the industry today to deliver amazing visuals, such as the showdown demo from Epic Games:

The showdown demo from Epic Games

These guys were able to render this amazing scene at 90 FPS. There is transparency, lighting, and visual effects. The models used are from various other UE4 demos and are not reduced in quality. Here is just some of how they did it.

...

Measuring ingame performance

Over and over again, I have mentioned-performance as the most important consideration for a VR game. Yet, we have not talked about how to measure performance inside Unreal Engine 4 so that we can know whether we are optimizing well or not. Let's take a look at the tools we have available.

UE4 has an amazing number of performance profiling tools available as part of the game engine, more than I could discuss in this one-quick-start guide. However, I do want to discuss a couple that are relevant to our discussion: the Stat commands and the GPU Visualizer:

Stat command statistics

There are several Stat commands that can be useful for us to determine our performance. They are accessed by opening Accessing the console with the tilde key and typing in the following commands (they are not case-sensitive):

• Stat FPS: This command brings up the current...

Summary

In this chapter, we learned several of the known causes of performance issues in VR games related to static and skeletal meshes, materials, lighting, and visual effects. After discussing the causes, we explored several different solutions using some examples from the DJ simulation Tribe XR and Epic Games own the cinematic VR demo showdown. Lastly, we discussed methods for profiling our own game performance to determine whether our game is being limited by the CPU or GPU, and how we can use that data to adjust and optimize our application for maximum player comfort.

In the final chapter, we will discuss the importance of game testing in the user experience design process and how to collect that data to make further design decisions. We will also learn how to finalize our game through the cooking process and prepare it for distribution. Finally, we will discuss the importance...