Ray Tracing Can Render Realistic Shadows & Reflections, Can Also Improve AI & Collision Detection

Imagination’s Alex Voica explains how PowerVR Ray Tracing provides an efficient solution for video game graphics.

powervr ray tracing

Image Credit: Anandtech.

Although there are a few games like Killzone Shadow Fall that use Ray Tracing, the technology is still pretty difficult to implement in video games. Not too long ago, we wrote about the potential of DirectX 12 in implementing ray tracing on the Xbox One and although theoretical scenarios exists not many retail games uses them.

GamingBolt was able to get in touch with Imagination who are working on ray tracing technology called as PowerVR Ray Tracing. Imagination is a leading technology company that deals in providing tools for graphics, video, communications and processing. Their 64-bit MIPS architecture based CPU were used in PlayStation 2 and PlayStation Portable.

Speaking to Alex Voica, who is the Marketing Communications team at Imagination, GamingBolt asked about the potential that PowerVR Ray Tracing holds in changing video game graphics.

Ray Tracing is mostly used in movies [like Avatar] but according to Alex there is no reason why it can’t be used in a video game. “Even though most people think ray tracing is only useful for non-real time photorealistic, physically accurate rendering for things like movies and adverts, there is absolutely no reason why it cannot be used in real-time renderers for games, especially since there is now efficient hardware support for accelerated ray tracing in the PowerVR Wizard GPU family.”

Alex then talks about the advantages of using Ray Tracing over raster techniques. “The main use for ray tracing in rendering is to accurately simulate effects such as hard and soft shadows, transparency, reflections or refractions. All these ray tracing-based effects are easy to implement, they do a better job approximating the physical light transport phenomena, and they avoid the artefacts of even the more sophisticated raster techniques. “

“Additionally, they can be more efficient.  Ray traced shadows allow for per-pixel sampling decisions so there is much less waste in scenes with many shadow casting lights.  Moreover, ray tracing reflections are a big win over using dynamic reflection maps in scenes with many reflective objects.  This is because there is no need to perform a separate rendering pass for each object when you can trace rays for the pixels that are visible. “

Finally Alex explains how Ray Tracing could actually help in other features like collision and AI. “While the primary application of ray tracing is rendering, there is nothing that prevents it from being used for other purposes. There are many applications that would benefit from the ability to know the entire layout of the scene and can use ray tracing independent of rendering; physics and collision detection or visibility detection in AI are two perfect examples. “

“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. This 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.”

What do you think about Ray Tracing? Let us know your thoughts in the comments section below.

This is just a snippet from our interview with Imagination and we will have more in the coming weeks.


  • ME3X12

    ESRAM and DX12 will excels greatly in this and will have a big advantage over PS4 in a few years when this becomes more common.

  • GHz

    This could add to this discussion if you have the patience to watch it. It’s about how GG implemented ray Trace in KZSF.

    http://youtu.be/_29M8F-sRsU

    Devs have been giving us info on the unique differences between these machines. It’s no surprise that you’ll only see their strengths materialize when games are specifically designed for each of them.

    “Our contacts have told us that memory reads on PS4 are 40-50 per cent quicker than Xbox One, and its ALU (Arithmetic Logic Unit) is around 50 per cent faster.”

    “Xbox One does, however, boast superior performance to PS4 in other ways. “Let’s say you are using procedural generation or ray tracing via parametric surfaces – that is, using a lot of memory writes and not much texturing or ALU – Xbox One will be likely be faster,” said one developer.”

    http://www.edge-online.com/news/power-struggle-the-real-differences-between-ps4-and-xbox-one-performance/

    in this interview, should we believe only the merits attributed to the PS4? Shouldnt we consider also what he said about the XB1 strengths as truth?

    In the end it’s all about the games right?

    • Anon

      That’s a separate matter referring to post-processed screen-space reflections. It relies on the rendering still having been done with standard techniques.

      This article is talking about near-full light transportation done entirely with path-tracing and dedicated hardware like what PowerVR has been working on. As visibility checks and collision tracing is very common, not to mention expensive, dedicated ray tracing hardware would be ideally suited for accelerating areas outside of rendering too. Advances in real-time sound processing/DSP could be possible too, as the way sound moves through an environment is somewhat analogous to the way light moves.

    • GHz

      Yeah, in the end of the vid they explained it all. Not exactly the kind of ray tracing this article is talking about. It’s informative in that Rashid Sayed mentioned KZ. watching the vid gives you the truth about that being that the info came straight from the KZ devs themselves.

      I appreciate your input.

    • JerkDaNERD7

      Not real-time ray tracing but great implementations nonetheless.

  • JerkDaNERD7

    I always ask myself this question. Why didn’t Microsoft just choose a PowerVR chip?! My guess would be because AMD SoC with graphics might have been better or probably too expensive, who knows.

    It only makes sense that if the Xbox One’s architectural design is similar to tile-based devices with PowerVR chips they would just go all out rendering the whole graphics screen through tiling.

    • ME3X12

      No they had to keep it close to what is best for developers but at the same time give the design the edge when doing this form of technology and that’s what MS did so in a few years when this is used much more the X1 will have big advantages in this stuff. The PS4 was designed for brute force right out the gate the X1 was designed more elegantly with much more forward thinking in mind for future technology.

    • JerkDaNERD7

      Yes that does make a lot of sense. The last console that utilized rendering everything through tiling was Dreamcast I guess, and it used a PowerVR. The only problem were developers wanted to stick to the conventional method.

      Guess it only makes sense that Microsoft wanted to give developers options between conventional and tiling (textures/lighting) methods. Otherwise it would have been much worst than recent events.

  • ChatWraithGamma

    Since DX12 isn’t out it’s hard to tell what kind of computing room it’ll save, but realtime, true mental ray is immensely expensive. That isn’t something we’re going to see for easily another decade or more.

    Currently, people use mental ray and other passes to render out scenes for film and other CGI in batch rendering. One frame at a time, about 1 frame every 30 seconds or so. Minutes of footage can take days to render out fully, and usually done in pieces on groups of supercomputers. Maybe on a couple Titan Z’s in tandem, this could be done, or perhaps if the scene was incredibly simple, but otherwise impossible for a consumer machine, or current gen game consoles.

    A partial solution like this looks cool, but it isn’t true raytracing/light simulation.

  • Malaika Thomas

    he hasn’t explained using ray tracing in what way, you vcant just render everything in realtime with ray tracing even killzone uses it just for water puddle’s reflections, this author has no clue of what he wrote.

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