NVIDIA has showcased new tech they are calling NVIDIA RTX Direct Illumination. In short, this new rendering algorithm is a game developer-ready RTX feature that allows devs to make use of more light sources in a video game engine and let them all cast light and shadows without the cost of resources. We are talking about millions of light sources that will enable developers to create more realistic scenes without the need for a traditional “hero light” setup.
The new NVIDIA RTX Direct Illumination tech bypasses the “hero light” setup that games have used up to this point. This rendering method would usually task one or two lights in a video game to brighten up the scene and cast shadows while the other lights would “fake” illumination. This meant that most of the other lights in an environment would act in an “unnatural” way without shadows and other light bounces.
This is where the new NVIDIA RTX Direct Illumination tech comes in. The tech combined raytracing with an advanced version of the ReSTIR algorithm and some other advanced learning algorithms to allow for light to be applied on secondary surfaces. This means that engines using this new NVIDIA RTX Direct Illumination tech will be able to have multiple light sources that all act and behave as a “hero light”. This will enable for much more realistic scenes as lights will bounce and shine as it does in the real world.
NVIDIA says that the new NVIDIA RTX Direct Illumination tech does not affect performance and developers will be able to create scenes with dozens, hundreds, thousands and even millions of lights and the resource costs will be kept to a minimum. The tech also works alongside NVIDIA DLSS to machine learn higher resolutions and frame rates without compromising hardware.
The new tech is also developer-friendly. According to NVIDIA, designers can target light sources and have them act naturally without having to manually input each source and direct its light output. An example of this is a silent stealth game where light sources may reveal your location. Players will be able to disable lights and they will cast pure shadows now depending on the other light bounces in the scene.
NVIDIA has created the new NVIDIA RTX Direct Illumination tech to be hardware-agnostic which means the feature will work across not only AMD GPUs but also the PS5 and Xbox Series X/S. This is due to the console APIs support.
The demos that NVIDIA showed off look rather superb and it goes to show how important light is in a video game scenario. While the tech is new and won’t be seen in a video game for some time now, it does mean that one day we can play games that make use of the NVIDIA RTX Direct Illumination.