Epic talks shop about stuttering in games that use its Unreal Engine and offers solutions to the problem

pcgamer.com:

Mention the words 'Unreal' and 'Engine' to a PC gaming enthusiast, and they will no doubt immediately think of incredible-looking graphics, as demonstrated in the likes of Black Myth: Wukong, Senua's Saga: Hellblade II, and A Plague Tale: Requiem. However, there's probably one other thing that PC gamers associate with Unreal Engine and it is stutter. If you wondering just what that is and why it happens, the maker of UE has explained it all in a new blog and detailed just what it's doing to prevent it.

Let's start at the beginning. Shaders are small pieces of code that are used in graphics rendering to do a very specific task. It might be just to move a triangle about a screen or it could be for something such as calculating the colour of a pixel, based on multiple light sources, materials and other effects.

Unreal Engine is a game development tool that you program in C++ or via its built-in code blocks, called blueprints. To make it much easier to code graphics, an API such as Direct3D or Vulkan is used (application protocol interface), where you can issue one instruction and the API will then turn that into multiple other instructions for you.

However, the GPU in your graphics card doesn't understand anything that the API spits out, so its drivers need to convert the code into a format that it can process. This is generally called shader compilation and in a modern, complex 3D game, there are tens of thousands of shaders that need to be compiled.

If the game tries to do this while you're playing it, the CPU will be too busy compiling the required shaders to run the game at full speed, albeit somewhat briefly, and the game's frame rate will suddenly drop. It then bounces back up once the compiling is done, and when this repeatedly happens over and over, you get stuttering. For Unreal Engine, as Epic describes it in more detail:

"Rendering an object usually involves several shaders (e.g. a vertex shader and a pixel shader working together), as well as a number of