Added ray tracing low level support. Implemented a low level layer on top of UE DirectX 12 that provides support for DXR and allows creating and using ray tracing shaders (ray generation shaders, hit shaders, etc) to add ray tracing effects.Added high level ray tracing features. Rect area lights. Soft shadows. Reflections.
Reflected shadows. Ambient occlusion. RTGI (ray traced global illumination). Translucency. Clearcoat. IBL.
Apr 19, 2019 - Meaning I did not have the support of the new RTX cores and my results should not be indicative of actual RTX powered raytracing in Unreal. Apr 01, 2019 Getting Started with Ray Tracing in UE4. Getting started with ray tracing for your own project is simple. Simply opt-in to the renderer settings for ray tracing and the GPU skin cache. Epic includes instructions on enabling things to test them out here, as well as a.
Sky. Geometry types.
![Sheets Sheets](/uploads/1/2/5/3/125355942/632105392.jpg)
Texture LOD. Denoiser. Path tracer.
10:57 - Interesting that they explicitly call out that you can actually get faster performance with Raytracing in some situations versus cascaded shadow maps. In particular, large outdoor environments is where they'd expect developers to focus on ray tracing initially, and with close quarter environments using it more sparingly.Oh, and the fact they make sure to point out that in those larger scenes, you won't see the edge of the shadow maps (since there are none.). As someone who gets annoyed by that visual artifact in games, that is going to be interesting to see once a game implements it. It's one of those how long is a piece of string questions. The reason why RTX works so well is because most of the color of the pixel is generated by rasterization so you can pick up additional color values from the rays using only a couple of rays per pixel and still be within a first order of approximation to the correct pixel color.
You have water? Two rays, reflection and refraction. Bounce them, what's the color of the texture that it hits? Mix it with the rasterizer's color appropriately and bam, water for that pixel done. It doesn't account for other indirect bouncing but that's only going to be.barely. perceptible once you're in motion.
Dumping the rasterizer and losing all of that lovely fairly accurate color data for the scene is going to be a tough sell.Once you get into path tracing like the Q2VKPT the accuracy starts to depend on how many rays per pixel make the image acceptable. You can see a hell of a lot of noise even with the engine being run through a denoising filter. In the case of Q2VKPT, the materials being used are simulated as having one bounce with two rays. Once you start getting into exotic materials of modern day where you have fine grained levels of ambient, diffuse, and specular levels, you have to cast more rays to get acceptable levels of noise if you're building the image from scratch. If you're only throwing out two rays how do you tell the difference between a material with a smoothness of 0.4 and 0.6? The UE4 video has a filter that shows raytracing complexity of the scene.
That's the engine computing how many rays it needs to throw out to get fairly accurate color data based on the material specifications of the material on that pixel.And therein lies the crux. How many rays do you want to throw out? How many have you got? Double it and the engine will still probably want more. Will it look good enough? It's realtime. The frames are ephemeral so they don't have to be perfect.
But at the same time, they can't look like garbage either. We're trying to improve over rasterization here.