Ray tracing technology in graphics technology is now a mainstream application technology for desktop and game consoles with great success, and at Imagination, we believe that it is time to apply its benefits to mobile devices. In addition to providing more realistic visuals for end users, it also simplifies the workflow for developers, saving them time by not having to spend hours manually placing lights in their scenes. Through ray tracing, a light source is placed in the scene, and ray tracing can automatically and dynamically process lighting effects. It also provides instant feedback on how the scene looks, giving developers more time to perfect other work.
Imagination’s latest GPU, IMG DXT, supports ray tracing and also supports FSR (Fragment Shading Rate), a feature designed to allow developers to perform less shading on specific render targets, freeing up GPU performance for other effects . Having this feature could change a developer's ability to deploy ray tracing in games.
DXT is architected to allow device manufacturers to deliver incredible ray tracing performance to flagship mobile devices. At the same time, based on its scalable design, DXT can also provide various levels of ray tracing to meet the needs of mainstream devices at a more affordable price.
Customers interested in area efficiency can choose to deploy the DXT-8-256, a device with 0.5 Ray Acceleration Cluster (RAC), ensuring 8 GTexels/s, 256 GFLOPs (more than 20% higher performance density than previous generations), 216 MRay/s performance.
This is only 60% of our standard solution for ray tracing. It is worth noting that all our solutions belong to level 4 of the Ray Tracing Level System (RTLS) regardless of how much ray tracing is taken. This ensures high efficiency and usable Optimal utilization of hardware.
On the other hand, for high-end equipment where high-end performance is critical, the DXT-72-2304 provides an ultra-high 72 GTexels/s and 2.25 Teraflops computing power, and provides optional up to 3 RACs and 1.3 GRays of rays Track performance.
The Ray Acceleration Cluster is part of the Photon architecture (introduced at the same time as the CXT GPU system), the first GPU IP to provide hardware acceleration for ray tracing. The RAC consists of a tester unit that searches for rays that intersect objects in 3D space; then the hardware also contains a scheduler and ray tracing memory that allow us to do ray traversal in hardware. Finally, our hardware also supports coherent collection, which analyzes all active rays and creates groups of coherent rays to test the scene together. This is a unique patented technology that supports parallel testing to better match the characteristics of GPU parallel computing, resulting in higher efficiency.
In addition to the scalability of RAC, DXT also has a new technology based on VK_KHR_fragment_shading_rate extension. FSR (Fragment Shader Rate) refers to the number of times the fragment shader runs. Reducing this number means the GPU can do less work, which reduces power consumption and, with efficient use, almost no loss in image quality. With FSR technology, the scene is divided into "regions", each region applies a different shader execution rate. Developers can specify shader rates using one of three methods: rendering pipeline (Pipeline, draw call), rendering primitives (Primitives), and attachment (Attachment).
This gives developers control over how GPU performance is used to maximize visual performance on power-constrained mobile devices. Therefore, developers can choose how to actively use FSR technology. If the object is far away or the background is far away, they can use the fragment shader every 16 pixels. If the objects are detailed and closer, they run a standard one fragment shader per pixel. A 1x2 or 2x1 pixel grid array "medium" mode will save up to 50% power.
What is important for ray tracing scenarios is that FSR means fewer rays are sent into the scene, and when combined with denoising, similar visual effects can be achieved at lower power costs or with more area-efficient hardware, such as in Half of the RAC configuration is used on the DXT-8-256. The combination of FSR and ray tracing brings greater graphical realism across a wider range of performance points, enabling ray tracing technology to bring a better experience to users in the mobile field.
Original link: https://blog.imaginationtech.com/ray-tracing-and-fragment-shading-rate-fsr-in-img-dxt-a-match-made-in-heaven
Disclaimer: This article is an original article, and the author, source and original link must be indicated when reprinting.
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