In the utter desolation after the first conference on March 18, Epic Games floods the now parched sonar souls with a gameplay / tech demo of theUnreal Engine 5 on PS5. If I had to describe Lumen in the Land of Nanite, the title of the demo, with one word, I would use the word future. But not for the graphic quality, physics and sound shown.
Of course, the eye also wants its part and has had it, thanks to one of the gameplay graphically more incredible ever. But it is the technology that has allowed us to create that interactive masterpiece that is truly incredible. A technology until now only mentioned in the science fiction books of developers and 3D artists. So I want to take you with me to explore these technological wonders, explaining why Lumen e nanite, the two innovations introduced, mark a point of no return in the development of video games.
Nanite: for geometries without borders
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La polygonal count of the 3D models, the number of triangles that make up a mesh, has always been a Sword of Damocles aimed at the neck of both developers and 3D artists. The more a model has a high polygon count, the more the 3D artist will be able to work in detail, be it an organic character or a mechanical vehicle. But these polygons, through the rasterization process, will then have to be drawn on the screen one by one in real time. It is therefore well understood that the more polygons to be drawn, the more computing power will be needed to maintain a stable framerate. How then to create a graphically fascinating model without behead the GPU?
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Up to now, several methods have been used simultaneously for fool the human eye. For organic characters, for example, a process is used that is called in jargon bake of normal. Once the character has been defined down to the smallest detail with a sculpting software such as ZBrush, through a partly automatic and partly manual procedure called retopology, a much less detailed model is created from the original. It will be the latter that will actually be used in thegame engine, but one will be applied to it special texture, called normal, which maps the details previously created. This texture is created through special tools that examine both models and map the details of the model high poly on the normal texture to be applied to the model low poly.
It therefore seems that the problem is solved, using a low poly model but with a texture that simulates the most precise details. Unfortunately, however, this polygonal decimation process requires several hours of work and long waiting times. But from what we saw with the Unreal Engine 5 tech demo on PS5, much of this can finally come to an end.
nanite will allow you to scale and stream the geometries in real time, allowing you to import models with any polygon count. Whether they are derived from Zbrush, photogrammetry or CAD. Models that will finally have a very high level of detail, like in offline cinematic rendering, without the need for special normal textures.
Lumen: photorealism even without ray tracing
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Ray tracing and the importance of light in video games
Let's clarify a fundamental point immediately: Lumen is not ray traced. Lumen is a new dynamic implementation of Global Illumination, a global lighting technology already in place in realtime rendering systems such as Unreal and Unity. And it is precisely because it is not ray tracing that it is truly incredible. In fact, Lumen allows you to calculate infinite bounces of reflection diffuse maps (basically the textures that give the various color tones to the 3D model) and one huge amount of mirror reflections (specular is the degree of reflectivity of an object, how much other nearby models affect its material). And all this for scales ranging from a few millimeters to several kilometers. For example, artists will be able to change the angle of the Sun and see in real time how the environment changes, at highest possible quality.
Bakinkg takes up a huge amount of hours ...
Said so it seems a trivial improvement, but I assure you it is not. To obtain the maximum quality of lighting within a realtime environment, it is necessary to start a process called Lightmap baking in the development phase. This process calculates the membership physical behavior of light for all objects on stage. It will then produce a map of lights which will be used to render the final image of the environment. The problem with this process is that it requires a huge amount of hours, during which the engine engulfs all the hardware it has at its disposal.
Being able to make changes to lighting and see the effects at the highest quality in real time is a huge advantage. Both in terms of timing, both as regards the artistic quality. Immediately observing the change that has just been made, allows you to immediately understand whether what has been done is improving or pejorative. Waiting for the end of a long process leads to not a little distorting the perception of what had been done.
Unreal Engine 5 on PS5: the developers thank
A tech demo is a presentation of the maximum potential software, not to be confused with a video game demo.
So we understand that what the Unreal Engine development team really did, is reset the dead times that have nothing to do with the artistic process and with the programming of the game. Processes that have always been hated by every developer / artist, found to be boring and pedantic. Now that they finally have been in part released from this yoke, they will be able to devote themselves to much more interesting tasks, to the benefit of us gamers.
It is not easy to show the general public how much of the technological improvements low level can also improve the end user experience. Epic Games has hit the target in full, ecstatic both gamers and professionals, with an exciting tech demo from every point of view. There is a passion fordigital art and at the same time for the technology which supports it, in a unique symbiosis, as only video games can create.