2015 iPhones and iPads could achieve photorealism with ray-traced graphics from Imagination

PowerVR GR6500 (raytracing 001)

Imagination Technologies, a fabless UK-based semiconductor maker, has been supplying PowerVR-branded mobile graphics IP for Apple’s in-house designed iDevice chips since the iPhone’s inception.

Detailed 3D graphics, speedy animations and smooth performance have always been one of the hallmarks of the iPhone and iPad so it’s no surprise that Apple is an investor in Imagination.

Following Imagination’s announcement of a next-generation PowerVR GX6650 GPU that promises to smoke graphics giant Nvidia’s own Tegra K1 mobile processor, Imagination yesterday said it is taking PowerVR graphics architecture to the next level by adding ray-tracing capabilities.

Apple likely won’t utilize this technique in its upcoming A8 chip for the iPhone 6 and 2014 iPads because Imagination’s technology won’t be making its way into products until 2015.

This means that come 2015, your iPhone and iPad could easily give dedicated game consoles a good run for their money graphics-wise, by supporting high-quality lighting and shadows, accurate transparency and photorealistic reflections…

What’s raytracing?

Currently, Imagination’s GPUs used in iOS devices – like the vast majority of mobile and desktop GPUs out there – use rasterized-only rendering. This basically applies bitmap textures to 3D surfaces and then adds basic lighting and shadow effects.

This rendering technique is really fast and effective, but 3D scenes lack depth and photorealism because it doesn’t take into account complex lighting attributes.

Ray-tracing, on the other hand, traces the path of light through pixels in an image plane to accurately simulate the effects of its encounters with virtual objects, such as reflection, refraction, scattering, chromatic aberration and more.

As a result, surfaces feature photorealistic reflections and whole scenes have a high degree of visual realism. Because ray-tracing requires significant computational power, it’s mostly used for realistic visual effects in Hollywood movies and in industrial design, mechanical, architectural modeling and more.

Now, Imagination claims it’s been able to combine best of both worlds by coupling ray tracing to traditional rasterized graphics. The end result looks something like this.

PowerVR GR6500 (raytracing 005)

Check out those reflections! Cool, no?

The new GPU design is conveniently named ‘Wizard’ and can deliver a whopping 300 million of rays per second. Also, ‘Wizard’ generates ray traced graphics in real-time and scales from mobile to mainstream gaming PCs to dedicated gaming consoles, the company claims.

And this is how ‘Wizard’ improves AI in games, as per Imagination:

For example, characters in a first-person shooter can start to see and understand the 3D environment around them, using the ray tracing to process spatial understanding opens up a new world for realistic behavior when in-game agents can make decisions based on direct line of sight calculations that model what they are able to see.

To give you a better feel for how ray-tracing improves 3D graphics, check out the below side-by-side example of standard rasterized-only rendering (left) versus ray-tracing (right).

PowerVR GR6500 (raytracing 003, rasterized)PowerVR GR6500 (raytracing 004)

The PowerVR GR6500 is Imagination’s first Wizard-enabled GPU.

The chip supports a range of APIs such as OpenGL ES 3.1/2.0/1.1, OpenGL 3.x, Direct3D 11 Level 10_0, OpenCL 1.2, and OpenRL 1.x and has additional ray tracing-specific hardware that includes:

  • Dedicated ray tracing data master that feeds ray intersection data to the main scheduler, in preparation for shaders to run, which evaluate the ultimate data contribution from the ray.
  • Specialized Ray Tracing Unit (RTU) which uses fixed-function math to perform ray tracing intersection queries, in addition to gathering ray coherency in order to reduce power and bandwidth consumption.
  • Scene hierarchy generator to speed up dynamic object updates.
  • Frame accumulator cache that provides write-combining scattered access to the frame buffer.

Imagination’s ray-tracing tech is picking up support from game developers.

PowerVR GR6500 (raytracing 002)
An example scene created using Imagination’s PowerVR ray-tracing tech.

Yesterday, Unity said the latest incarnation of its popular game engine, Unity 5, supports Imagination’s PowerVR ray-tracing technology to give game designers near instantaneous feedback on changes to lighting in-scene during development.

Apple’s in-house designed A7 chip that powers the iPhone 5s, iPad Air and iPad mini with Retina display uses Imagination’s PowerVR G6430 graphics package.