Epic Games made a significant announcement today regarding the fifth generation of Unreal Engine. The company put up a video demo that they claim is running off of a PlayStation 5. Assuming those claims are valid, players are going to be in for a treat when the next console generation drops.
Titled "Lumen in the Land Of Nanite," the demo runs about seven minutes, with an introduction by two of Epic Games' technical directors prefacing it. The demo is intended to show off the two core technologies of Unreal Engine 5, a lighting system called Lumen, and a virtualized geometry system called Nanite. Below are two images from the early part of the video.
Global illumination, involving techniques such as ray tracing and ambient occlusion, has previously been restricted to high-end rendering packages, which take multiple hours and multiple passes to display the scene accurately. Real-time engines haven't had the horsepower to make that sort of detail possible. This is why recent announcements like the addition of ray tracing in Minecraft are such a big deal.
According to an article from Eurogamer, Unreal Engine 5's Lumen system will allow for hardware ray tracing to be possible, though it was not used in the demo today. Even so, one of the tricks a real-time engine uses typically, known as a lightmap, was not present in the demo.
One example of lightmapping would be a streetlight aimed down at a sidewalk. In the demo, situations that could have been lightmapped, such as the girl's passage through the tunnel or a later section where she's shining a light on walls, were all generated dynamically. It is possible to have global illumination without ray tracing, and the demo demonstrates it's possible to do it in real-time.
The Nanite technology is what is known as a micro-polygon engine. Currently, character meshes and other assets are comprised of smallish but still discrete triangles. However, the number of triangles used to create a character in something like Maya or Blender initially are radically reduced when they're exported as assets for Unreal or Unity.
There are ways to trick the eye into thinking there's more there than what is in place, such as normal maps to give textures more depth. But this is why, when you approach large objects in some games, there is a "pop-in" effect where the purpose seems unusually blocky and or blurry before snapping into a more detailed version.
Objects right now require a built-in level of detail settings to help cut down on the number of triangles that the engine has to try and render. This also explains why you often see "fog" off in the distance where landscape details pop-in as you start to approach them.
For a while, voxel engines were considered a possible way forward to improve the level of detail by creating volume points on a 3D matrix. Still, they've usually been relegated to supplementary status or for games such as Trove. The physical horsepower and the software shortcuts needed just weren't there. Even John Carmack tried playing with voxels in the Quake III engine before giving upon them.
In a micro-polygon engine, every triangle can effectively be a pixel (trixel?), which means that you don't need normal maps to make something look more textured, and you don't need to set LOD distances for objects. Your characters, your props, your object models, even terrain models can theoretically be as elaborate as you can make them, and the engine will not choke on rendering them as they were created.
When you combine the two technologies, you have a quantum leap in real-time rendering. While the Eurogamer article pointed out that the demo today was running in 1440p resolution at 30 FPS, that's still pretty impressive as the first effort for an engine that has not yet been officially released.
Epic has indicated that they are looking to ensure forward compatibility with existing projects in Unreal Engine 4, and want to make a move to Unreal Engine 5 as painless as possible for developers of all stripes. To help further ease the pain, Epic also announced that starting today, the royalty threshold for Unreal Engine licensees has been increased to $1 million, and that threshold is retroactive to the first of this year.
This means that game studios that use Unreal Engine, version 4 or 5, basically get to keep the first million dollars in gross revenue before Epic starts imposing the 5% royalty payment requirement. Unreal Engine 5 is slated to be available in a preview capacity sometime early in 2021, with a full release towards later that year.