6 ms·

PowerVR GR6500: Ray tracing is the future and the future is now

179 points by filipncs 13y ago

modeless 13y ago
John Carmack is a fan: "I am very happy with the advent of the PVR Wizard ray tracing tech. RTRT HW from people with a clue!" https://twitter.com/ID_AA_Carmack/status/446021820290842624 https://twitter.com/ID_AA_Carmack/status/446021820290842624
fidotron 13y ago
It's best to remember that ray tracing isn't the be all and end all of graphics since it's far harder for artists to control the results than the other hacked up ways. One consequence of this is their example comparison, where I think it's entirely subjective to say the ray traced output is better. Neither is particularly great. The big win is around indirect lighting, but the development of that in standard rasterisers in the last decade has exceeded even my wildly optimistic expectations. New options = good, but there's no such thing as a graphics silver bullet.
- banachtarski 13y ago
  Imagine you were an artist trying to light an indoor room. Would you rather have to place hundreds of small lights everywhere and experiment for days or weeks to get the correct ambient glow? Or would you rather stick a big sun outside and call it quits? There's a reason Pixar is using physically based lighting to construct all their scenes.
- klodolph 13y ago
  You might feel differently if you ever had to do shadow mapping on traditional hardware. Even in AAA games, there are tons of artifacts in the shadows. Same goes for reflections. I don't see why it's harder for artists to control the results... can you elaborate? It seems like it's going to be 90% the same. You have a point on a surface, you have a camera vector and light vectors, you supply a small piece of code and out pops a color. The major differences in the pipeline are in the scaffolding: depth tests, reflections, and shadows will be done in different ways. The differences for artists are that they'll have to learn a system with different limitations. My guess is that game graphics are going to follow the developments in movie CGI. Pixar switched to ray tracing in 2013, and games will switch when hardware powers up and expertise filters down.
  - jjoonathan 13y ago
    > The differences for artists are that they'll have to learn a system with different limitations. If current-generation AAA games are any indication, either very few artists ever learned the raster workarounds or few artists ever had time to implement the workarounds. I think ray-tracing will be a game changer. Raster shadows are easy to get subtly wrong and very difficult to get right. Cube-maps are easy to get subtly wrong and very difficult to get right. Transparency is easy to get subtly wrong and very difficult to get right. The list goes on. > Even in AAA games, there are tons of artifacts in the shadows. Same goes for reflections. Exactly! I can't count the number of times I've seen shadows pointing in the wrong direction, having the wrong color, having the wrong penumbra/antumbra, casting through solid objects, etc. Cube-map reflections are even worse (yay for faucet handles reflecting forrest scenes) especially when they're moving. Expect to see a reflection slide up the body of a car as it comes to a stop? If you're not in a car-racing game, forget about it. All of those problems can be overcome with artist sweat and tears. The code has already been written and is in the big engines, but the effects still regularly fail to happen in AAA titles. Ray-tracing makes it easy to do things right. None of the raster techniques have achieved that landmark. This WILL be a game changer.
    - stcredzero 13y ago
      So, is it the case that increasing computational resources help us with getting things right? It's generally good to bet with Moore's Law.
  - leoc 13y ago
    See my other comment https://news.ycombinator.com/item?id=7427486 https://news.ycombinator.com/item?id=7427486 .
- tinco 13y ago
  I'm sorry man, but that sounds crazy. Raytraced scenes are much easier for artists to control the results because things actually behave like you would intuitively expect (if the amount of rays is high enough). If raytraced scenes were hard to control, why would every single animated movie be raytraced? Raytracing really is the be all and end all of graphics. The more rays you can render, the more realistic your scene will be, up to 100% realism. Of course, we can come pretty far with the hacks as well, and it's hard to say if hardware raytracing can come close to the quality hardware shader hacks can achieve on traditional GPU's in real time.
  - agumonkey 13y ago
    It's both true and false. The same reason movies still use light panes, make up etc etc. You don't want random pure reality[1]. [1] no really, you don't.
  - duaneb 13y ago
    Raytracing is just one tool in a bag of necessary algorithms. For instance, there's no obvious way to extend raytracing to offer indirect lighting—all existing algorithms offer some form of tradeoff. Furthermore, many effects are flat out a pain to render with raytracing: displacement mapping, subsurface scattering, anti-aliasing, and scenes where both speed of rendering and dynamic geometry are needed. All of those require substantial thought and are non-trivial to implement. And don't forget non-realistic graphics. The problems of rendering are unlikely to become inherently easier—I don't think raytracing will ever be "end all of graphics". And while "every singly animated movie" might be raytraced to some extent, it's highly unlikely any of them use pure raytracing to achieve the effect.
    - gfodor 13y ago
      Uh, what. Sampled raytracing is the most natural approach to indirect lighting, displacement mapping, subsurface scattering, and anti-aliasing. As far as non-realistic rendering goes I am not sure how this is relevant, you can alter the properties of light and still use ray tracing, and many effects use image based techniques anyway. Raster will die in the long run, it's pretty obvious.
- joesmo 13y ago
  I don't think so, not with modern tools anyway. Raytracing is in my experience the technology that most closely models the real world. Most technologies used in games even today are hacks, using precomputed values oftentimes derived from ray traced models. Raytracing is quite natural to work with because it simulates real world objects and does so in a realistic manner. The only difficulty might be caused by the lack of such real-time raytracing hardware as depicted here causing slower development as one has to wait for a scene or animation to render. IMO, raytracing is indeed the pinnacle of photorealistic rendering currently.
- jasonwatkinspdx 13y ago
  I'm sorry but there is a pronounced industry trend exactly against what you argue. Physically based rendering is winning out almost everywhere. A straightforward path tracer is capable of simulating nearly all the physics of light to any desired degree of fidelity. Part of why it's won out is that it's actually far simpler for artists to work in terms of real world material concepts vs tuning abstract parameters in fake models that can be coerced into to looking real. Eg "dusty metal with this albedo map" vs maps for parameters in some mutilated and extended phong shader.
  - james4k 13y ago
    Physically-based rendering has little to do with global illumination, and is only really about the BRDF [1] used for computing the final pixel color based on a number of inputs for that point in space. [1] https://en.wikipedia.org/wiki/Bidirectional_reflectance_distribution_function https://en.wikipedia.org/wiki/Bidirectional_reflectance_dist...
    - MrScruff 13y ago
      Well it's pretty hard to do PBR outside of a path tracer since energy conservation is a key concept.
- chongli 13y ago
  I've yet to see a single rasterised game come anywhere close to ray-tracing in the shadow department and that's what destroys immersion for me the most: low-resolution, aliased shadows crawling all over the place.
plaes 13y ago
Open source drivers is the future.. but it's nowhere now :(
- zanny 13y ago
  I see headlines like this and I'm like "are they still in the driver dark ages? Yep? Call me when they stop acting like a 2 year old and play ball in Mesa"
mjcohenw 13y ago
How about FP64?
- jjoonathan 13y ago
  They'd have to either sacrifice yield or sacrifice FP32 units. Also, if they put FP64 support in their gaming cards they wouldn't be able to charge scientists and engineers extra.
  - duaneb 13y ago
    > Also, if they put FP64 support in their gaming cards they wouldn't be able to charge scientists and engineers extra. Bingo. Not many entertainment problems demand such precision. Why not charge more for it?
    - jjoonathan 13y ago
      Well, if AMD had taken the need to get their GPGPU offering out the door seriously or if they had later taken the need for CUDA compatibility seriously then Nvidia would have had to compete. Alas, we're talking about a company that doesn't even think it's important for their installer to reliably replace existing drivers. The result: I get to pay through the nose for my predecessor's CUDA lessons. Yay.
  - Narishma 13y ago
    Wat. They don't make gaming cards nor scientific cards. They make GPUs that go into iPhones and iPads.
- chongli 13y ago
  Who is going to use FP64 in iPads and Android tablets?
higherpurpose 13y ago
What's the difference between ray tracing and path tracing? And could we have a path tracing chip? This demo was pretty impressive. I think they said they used 4 Titans at 720p. https://www.youtube.com/watch?v=aKqxonOrl4Q https://www.youtube.com/watch?v=aKqxonOrl4Q
- InclinedPlane 13y ago
  Ray tracing works backwards from the way actual optics works. It sends out a ray for each pixel and then finds out what it falls on then does math to figure out what it should look like. In a simple example, you have a few light sources and you trace a ray back to an object (polygonal surface), then you shoot off other rays from there toward the light sources (or you shoot off potential reverse reflection rays). If something is blocking a light source you adjust the amount of shadow being rendered or you bounce off of that surface again toward the light sources, and so on. Making it possible to render shadows, reflections, and so on with decent fidelity. In contrast to that technique you have "radiosity", where the illumination at each point on a surface is calculated based on its environment. Radiosity is better at rendering diffuse light, ray tracing is better at rendering reflected light. The underlying difficulty is that illumination is a maddeningly combinatorial problem. In principle every part of every object in a scene contributes illumation to every part of every other object. The light falling on a desk lamp from the LEDs of a clock also illuminates the desk itself, and so on. Radiosity and ray tracing attempt to solve those problems by making simplifying assumptions and performing a subset of the calculations necessary to illuminate and render a scene completely faithfully. In principle a more proper ray tracing algorithm would be to send out a huge number of rays in every direction for every image field ray, then follow each of those through their evolution, sending out yet more for surfaces each fall on, and so on. But that's far too computationally intensive (it's an O(n!) level problem). Path tracing is similar to these techniques but makes different simplifying assumptions. And the most important aspect is that instead of deterministically calculating everything in a specific way it uses a monte-carlo method of statistically sampling different "paths" then using the data to estimate the resulting illumination/image rendering. Path tracing results in a compromise between ray tracing and radiosity of being able to render both reflective and diffuse light well, though it has its own short-comings.
kayoone 13y ago
I dont know much about the differences but the samples images (like the yacht) don't look particularly impressive or real to me.
- girvo 13y ago
  Mobile. They can do that on mobile. :)
  - Pacabel 13y ago
    Today's mobile devices, especially the higher-end ones, are quite powerful. They offer more processing power, memory and storage than laptops did just a few years ago, and desktops just a few years before that. So I don't think that "doing it on mobile" is really that powerful of an argument any longer.
    - girvo 13y ago
      Real-time raytracing isn't something we've had on mobile. Which is kind of the point of this article...
- scotth 13y ago
  The water does.
- HCIdivision17 13y ago
  I don't think it _is_ super obvious. Rather, I think the goal is to properly fill in the scene with the very subtle clues we unconsciously look for. I had a similar experience working a bit with Radiance years ago. The output looked mediocre, at best, but it was reporting a real view of the scene; it's call to fame is that it outputs real energy values in physical units (like energy per unit solid angle or luminance or such). But despite the cartoony models I provided, it did demonstrate subtleties that weren't hacks (needed for this application), things that you wouldn't think to or bother implementing directly. This? This grabs a lot of needed visual artifacts faster and more correctly without crazy hacks (or so it seems - it does say hybrid rendering).
- 13y ago
bobsgame 13y ago
I for one welcome our new PowerVR overlords.
mey 13y ago
Two thoughts: I would love to see a video of a dynamic environment (aka actors/objects moving in a scene). Also, how long before cryptocurrency miners use these to gain step function over current gpus.
- duaneb 13y ago
  > Also, how long before cryptocurrency miners use these to gain step function over current gpus. I can't imagine these ever being cheaper than ASICs.
- lucian1900 13y ago
  > Also, how long before cryptocurrency miners use these to gain step function over current gpus. Ugh. Never. Computing a hash won't be any faster on these GPUs.
deleted 13y ago
[deleted]
herokusaki 13y ago
Would be fun if this relegated traditional GPUs to being used only for mining cryptocurrency.
bhouston 13y ago
Interactive raytracing is the future both in mobile and desktop. My project http://clara.io http://clara.io, an online 3D modeler + renderer, recently gained the ability to do embeded interactive ray traced 3D embeds using V-Ray (one of the best and most accurate renderers in the world). It works best on Chrome, Firefox and Safari: https://plus.google.com/u/0/+BenHouston3D/posts/DYq2RKJENC5 https://plus.google.com/u/0/+BenHouston3D/posts/DYq2RKJENC5 Here is another example: https://twitter.com/exocortexcom/status/443538733661704192 https://twitter.com/exocortexcom/status/443538733661704192 I can only see raytracing becoming more popular.
- s-macke 13y ago
  That's really great. Did you use emscripten or is the renderer programmed in Javascript?
  - ddorian43 13y ago
    its not rendered on the frontend, but in the cloud (read the twitter responses)
  - bhouston 13y ago
    It is cloud streaming, this is because we do not want to be limited by the CPU/memory capabilities of the client. V-Ray is an amazing renderer, but for complex scenes it can require +32GB and use up to 40 cores or even clusters of machines. We want to virtualize that infrastructure for our users.
eigenbom 13y ago
I'd wager that the current rasterising pipeline is more flexible than one based on raytracing - capable of generating a range of styles, not just photorealistic ones. And therefore having an extra dedicated chip for raytracing seems uneconomical. The comparison examples given in the article were slightly ridiculous. How does a non-reflective car represents 'traditional' rendering? Look at any great AAA game and you'll see reflections, refractions, radiosity, etc., that are all pretty amazing. I don't think that general demand will be there for alternative rendering hardware for quite a while.
- banachtarski 13y ago
  Those reflections and refractions and such rely on raytracing though so better ray-tracing hardware will help improve traditional pipelines as well (which are increasingly getting physically based). Also, there is nothing intrinsic about the rasterization pipeline that makes it more or less flexible that a ray-tracing one. In a physically based engine, I'd imagine you would be able to inject shader code on every bounce (for bump mapping, BRDF behavior, subsurface scattering, etc) as well as when the ray hits the lens. A good system would allow you to spawn more rays as need be or modify geometry like the current tesselation and geometry shaders. I think the important thing is that a physically based model would be amazing to work with from a graphics engineer perspective. No more crazy floating point hacks or occlusion tricks to get the desired effect. I'd rather the hacks be at the hardware level than the software level.
- dualogy 13y ago
  > I'd wager that the current rasterising pipeline is more flexible than one based on raytracing - capable of generating a range of styles, not just photorealistic ones Nope. I'd say the "raytracing pipeline" really does replace only the rasterization step, and once the triangle to draw is "found", you do whatever shading/lighting/fx/fragshader you want to draw it with? Wouldn't this be the most sensible approach? Rasterization in lay-man's terms really is just "figure out which triangle, if any, is 'hit' at this pixel", so a historically much faster and very neat hack to avoid the tracing of a ray.. But you don't get cheap soft-shadowing / ambient occlusion / reflect-refract and you'd need to do occlusion culling seperately for current-gen "complex" scenes to avoid a drawcall for all kinds of hidden objects. That's where at some point raytracing as it becomes more feasible also becomes much more attractive. Potentially also reducing geometry-LODing headaches etc..
leeoniya 13y ago
"life-like reflections"[1]? allow me to disagree. the reflection is too green. probably not the hardware's fault, or is it? [1] http://blog.imgtec.com/wp-content/uploads/2014/03/5_-PowerVR-Ray-Tracing-hybrid-rendering-1.jpg http://blog.imgtec.com/wp-content/uploads/2014/03/5_-PowerVR...
- leeoniya 13y ago
  hmm, looks better now on desktop than on phone
PhasmaFelis 13y ago
"... the potential that these technologies have to revolutionize the user experience from mobile and console gaming to virtual and augmented reality." I've been interested in ray-tracing since the early '90s, and I'm glad it's finally coming to real-time, but this isn't going to "revolutionize" shit. It's going to make 3D games and VR slightly prettier than they were. It's not going to enable new styles of gameplay or new modes of interaction. We will never again see anything like the enormous forward leaps in realtime graphics that happened during the '90s. I'm also a bit put off by their comparison showing that PowerVR has better reflections, shadows, and transparency than a raster engine with reflections and some shadows turned off and a very poor choice of glass-transparency filter. On another look, I don't even know what they're going for with the shadows. The rasterized image has "NO SHADOWS" printed right between the shadows of a building and a telephone wire, and their hybrid render has the light from the diner windows casting shadows across outside pavement in broad daylight. Bwuh?
jbverschoor 13y ago
The biggest problem here is content.. Producing content is the most expensive aspect of a game. Improvement in tooling and reuse are the only way we can actually properly use better rendering
- zurn 13y ago
  Wouldn't ray tracing make content production easier, needing fewer tricks to fake behaviour of light and shadow?
ilaksh 13y ago
I think the sample frames demonstrate that hybrid ray tracing is less realistic that pure path tracing. I hope that someone figures out how to make stuff like the Brigade 3 demos based just on feeding geometry and textures to hardware.
- deleted 13y ago
  [deleted]
Kiro 13y ago
I thought Wolfenstein 3D was an example of ray tracing but reading this article and Wikipedia it seems to be all about lighting effects. What do I misunderstand?
- faddotio 13y ago
  I think you're thinking of raycasting.
- din-9 13y ago
  It was an example of ray casting and not ray tracing.
zurn 13y ago
Interesting to see if they can sell this, as ~everyone is invested in doing OpenGL. Maybe if Apple put it in all their iOS devices...
ohwp 13y ago
I think the examples used are not very impressive. And I think path tracing (which is a kind of ray tracing) is more interesting for the future. A nice blog about real time path tracing is: http://raytracey.blogspot.nl/ http://raytracey.blogspot.nl/
stcredzero 13y ago
high-performance ray tracing, graphics and compute in a power envelope suitable for mobile and embedded use cases. If true, color me impressed!
zokier 13y ago
So what is the API and libraries like? Is there any sort of built-in OGL fallback or do devs need to write two completely different renderers? Is there standards relating to this; are any other vendors going to be implementing same API? Is this new hardware compatible with the older Caustic2 cards?
bond 13y ago
This brings back some memories. Used to do some experiments using POV Ray back in the day. I remember how slow the process was, it could take several hours/days to generate an image full of reflections, but in the end the results were usually stunning... Link: http://www.povray.org/ http://www.povray.org/
- beagle3 13y ago
  Oh, the memories ... Before it was renamed "povray", it was called "dkbtrace". I printed the entire dkbtrace source and studied it, to see how a real Ray Tracer worked; and through it, I learned how efficient vtbls work (it was 1990 C, and though C++ was already starting to become visible and popular, it was still "that new language that may or may not become popular" - dkbtrace implemented all the OO inside). Thanks, D.K.B.
r4pha 13y ago
It never fails to amaze me how powerful raytracing is. Last year I took an "Image Synthesis" class and did a quick presentation about a post I've seen here on HN about a raytracker in 1337 bytes [0]. It is amazing how such a small program can generate an image with depth of view, shadows and texture. 0: http://fabiensanglard.net/rayTracing_back_of_business_card/index.php http://fabiensanglard.net/rayTracing_back_of_business_card/i...
- touristtam 13y ago
  Thanks I completely forgot about that one. :)
Geee 13y ago
This is incredible! Mobile GPU does 300 million rays per second without using any shading GFLOPS? This is the GPU that is going to be on the next iPhone, right? Brigade 3 does 750 million rays per second on Nvidia GTX 580 with full power. I just wonder what this thing could do when scaled up.
touristtam 13y ago
is this not from the same guys? https://www.youtube.com/watch?v=rfgz90Y93c0 https://www.youtube.com/watch?v=rfgz90Y93c0 < google tech talk

179 points by filipncs 13y ago

John Carmack is a fan: "I am very happy with the advent of the PVR Wizard ray tracing tech. RTRT HW from people with a clue!" https://twitter.com/ID_AA_Carmack/status/446021820290842624 https://twitter.com/ID_AA_Carmack/status/446021820290842624

fidotron 13y ago

It's best to remember that ray tracing isn't the be all and end all of graphics since it's far harder for artists to control the results than the other hacked up ways. One consequence of this is their example comparison, where I think it's entirely subjective to say the ray traced output is better. Neither is particularly great. The big win is around indirect lighting, but the development of that in standard rasterisers in the last decade has exceeded even my wildly optimistic expectations. New options = good, but there's no such thing as a graphics silver bullet.

banachtarski 13y ago
Imagine you were an artist trying to light an indoor room. Would you rather have to place hundreds of small lights everywhere and experiment for days or weeks to get the correct ambient glow? Or would you rather stick a big sun outside and call it quits? There's a reason Pixar is using physically based lighting to construct all their scenes.
klodolph 13y ago
You might feel differently if you ever had to do shadow mapping on traditional hardware. Even in AAA games, there are tons of artifacts in the shadows. Same goes for reflections. I don't see why it's harder for artists to control the results... can you elaborate? It seems like it's going to be 90% the same. You have a point on a surface, you have a camera vector and light vectors, you supply a small piece of code and out pops a color. The major differences in the pipeline are in the scaffolding: depth tests, reflections, and shadows will be done in different ways. The differences for artists are that they'll have to learn a system with different limitations. My guess is that game graphics are going to follow the developments in movie CGI. Pixar switched to ray tracing in 2013, and games will switch when hardware powers up and expertise filters down.
- jjoonathan 13y ago
  > The differences for artists are that they'll have to learn a system with different limitations. If current-generation AAA games are any indication, either very few artists ever learned the raster workarounds or few artists ever had time to implement the workarounds. I think ray-tracing will be a game changer. Raster shadows are easy to get subtly wrong and very difficult to get right. Cube-maps are easy to get subtly wrong and very difficult to get right. Transparency is easy to get subtly wrong and very difficult to get right. The list goes on. > Even in AAA games, there are tons of artifacts in the shadows. Same goes for reflections. Exactly! I can't count the number of times I've seen shadows pointing in the wrong direction, having the wrong color, having the wrong penumbra/antumbra, casting through solid objects, etc. Cube-map reflections are even worse (yay for faucet handles reflecting forrest scenes) especially when they're moving. Expect to see a reflection slide up the body of a car as it comes to a stop? If you're not in a car-racing game, forget about it. All of those problems can be overcome with artist sweat and tears. The code has already been written and is in the big engines, but the effects still regularly fail to happen in AAA titles. Ray-tracing makes it easy to do things right. None of the raster techniques have achieved that landmark. This WILL be a game changer.
  - stcredzero 13y ago
    So, is it the case that increasing computational resources help us with getting things right? It's generally good to bet with Moore's Law.
- leoc 13y ago
  See my other comment https://news.ycombinator.com/item?id=7427486 https://news.ycombinator.com/item?id=7427486 .
tinco 13y ago
I'm sorry man, but that sounds crazy. Raytraced scenes are much easier for artists to control the results because things actually behave like you would intuitively expect (if the amount of rays is high enough). If raytraced scenes were hard to control, why would every single animated movie be raytraced? Raytracing really is the be all and end all of graphics. The more rays you can render, the more realistic your scene will be, up to 100% realism. Of course, we can come pretty far with the hacks as well, and it's hard to say if hardware raytracing can come close to the quality hardware shader hacks can achieve on traditional GPU's in real time.
- agumonkey 13y ago
  It's both true and false. The same reason movies still use light panes, make up etc etc. You don't want random pure reality[1]. [1] no really, you don't.
- duaneb 13y ago
  Raytracing is just one tool in a bag of necessary algorithms. For instance, there's no obvious way to extend raytracing to offer indirect lighting—all existing algorithms offer some form of tradeoff. Furthermore, many effects are flat out a pain to render with raytracing: displacement mapping, subsurface scattering, anti-aliasing, and scenes where both speed of rendering and dynamic geometry are needed. All of those require substantial thought and are non-trivial to implement. And don't forget non-realistic graphics. The problems of rendering are unlikely to become inherently easier—I don't think raytracing will ever be "end all of graphics". And while "every singly animated movie" might be raytraced to some extent, it's highly unlikely any of them use pure raytracing to achieve the effect.
  - gfodor 13y ago
    Uh, what. Sampled raytracing is the most natural approach to indirect lighting, displacement mapping, subsurface scattering, and anti-aliasing. As far as non-realistic rendering goes I am not sure how this is relevant, you can alter the properties of light and still use ray tracing, and many effects use image based techniques anyway. Raster will die in the long run, it's pretty obvious.
joesmo 13y ago
I don't think so, not with modern tools anyway. Raytracing is in my experience the technology that most closely models the real world. Most technologies used in games even today are hacks, using precomputed values oftentimes derived from ray traced models. Raytracing is quite natural to work with because it simulates real world objects and does so in a realistic manner. The only difficulty might be caused by the lack of such real-time raytracing hardware as depicted here causing slower development as one has to wait for a scene or animation to render. IMO, raytracing is indeed the pinnacle of photorealistic rendering currently.
jasonwatkinspdx 13y ago
I'm sorry but there is a pronounced industry trend exactly against what you argue. Physically based rendering is winning out almost everywhere. A straightforward path tracer is capable of simulating nearly all the physics of light to any desired degree of fidelity. Part of why it's won out is that it's actually far simpler for artists to work in terms of real world material concepts vs tuning abstract parameters in fake models that can be coerced into to looking real. Eg "dusty metal with this albedo map" vs maps for parameters in some mutilated and extended phong shader.
- james4k 13y ago
  Physically-based rendering has little to do with global illumination, and is only really about the BRDF [1] used for computing the final pixel color based on a number of inputs for that point in space. [1] https://en.wikipedia.org/wiki/Bidirectional_reflectance_distribution_function https://en.wikipedia.org/wiki/Bidirectional_reflectance_dist...
  - MrScruff 13y ago
    Well it's pretty hard to do PBR outside of a path tracer since energy conservation is a key concept.
chongli 13y ago
I've yet to see a single rasterised game come anywhere close to ray-tracing in the shadow department and that's what destroys immersion for me the most: low-resolution, aliased shadows crawling all over the place.

plaes 13y ago

Open source drivers is the future.. but it's nowhere now :(

zanny 13y ago
I see headlines like this and I'm like "are they still in the driver dark ages? Yep? Call me when they stop acting like a 2 year old and play ball in Mesa"

mjcohenw 13y ago

How about FP64?

jjoonathan 13y ago
They'd have to either sacrifice yield or sacrifice FP32 units. Also, if they put FP64 support in their gaming cards they wouldn't be able to charge scientists and engineers extra.
- duaneb 13y ago
  > Also, if they put FP64 support in their gaming cards they wouldn't be able to charge scientists and engineers extra. Bingo. Not many entertainment problems demand such precision. Why not charge more for it?
  - jjoonathan 13y ago
    Well, if AMD had taken the need to get their GPGPU offering out the door seriously or if they had later taken the need for CUDA compatibility seriously then Nvidia would have had to compete. Alas, we're talking about a company that doesn't even think it's important for their installer to reliably replace existing drivers. The result: I get to pay through the nose for my predecessor's CUDA lessons. Yay.
- Narishma 13y ago
  Wat. They don't make gaming cards nor scientific cards. They make GPUs that go into iPhones and iPads.
chongli 13y ago
Who is going to use FP64 in iPads and Android tablets?

higherpurpose 13y ago

What's the difference between ray tracing and path tracing? And could we have a path tracing chip? This demo was pretty impressive. I think they said they used 4 Titans at 720p. https://www.youtube.com/watch?v=aKqxonOrl4Q https://www.youtube.com/watch?v=aKqxonOrl4Q

InclinedPlane 13y ago
Ray tracing works backwards from the way actual optics works. It sends out a ray for each pixel and then finds out what it falls on then does math to figure out what it should look like. In a simple example, you have a few light sources and you trace a ray back to an object (polygonal surface), then you shoot off other rays from there toward the light sources (or you shoot off potential reverse reflection rays). If something is blocking a light source you adjust the amount of shadow being rendered or you bounce off of that surface again toward the light sources, and so on. Making it possible to render shadows, reflections, and so on with decent fidelity. In contrast to that technique you have "radiosity", where the illumination at each point on a surface is calculated based on its environment. Radiosity is better at rendering diffuse light, ray tracing is better at rendering reflected light. The underlying difficulty is that illumination is a maddeningly combinatorial problem. In principle every part of every object in a scene contributes illumation to every part of every other object. The light falling on a desk lamp from the LEDs of a clock also illuminates the desk itself, and so on. Radiosity and ray tracing attempt to solve those problems by making simplifying assumptions and performing a subset of the calculations necessary to illuminate and render a scene completely faithfully. In principle a more proper ray tracing algorithm would be to send out a huge number of rays in every direction for every image field ray, then follow each of those through their evolution, sending out yet more for surfaces each fall on, and so on. But that's far too computationally intensive (it's an O(n!) level problem). Path tracing is similar to these techniques but makes different simplifying assumptions. And the most important aspect is that instead of deterministically calculating everything in a specific way it uses a monte-carlo method of statistically sampling different "paths" then using the data to estimate the resulting illumination/image rendering. Path tracing results in a compromise between ray tracing and radiosity of being able to render both reflective and diffuse light well, though it has its own short-comings.

kayoone 13y ago

I dont know much about the differences but the samples images (like the yacht) don't look particularly impressive or real to me.

girvo 13y ago
Mobile. They can do that on mobile. :)
- Pacabel 13y ago
  Today's mobile devices, especially the higher-end ones, are quite powerful. They offer more processing power, memory and storage than laptops did just a few years ago, and desktops just a few years before that. So I don't think that "doing it on mobile" is really that powerful of an argument any longer.
  - girvo 13y ago
    Real-time raytracing isn't something we've had on mobile. Which is kind of the point of this article...
scotth 13y ago
The water does.
HCIdivision17 13y ago
I don't think it _is_ super obvious. Rather, I think the goal is to properly fill in the scene with the very subtle clues we unconsciously look for. I had a similar experience working a bit with Radiance years ago. The output looked mediocre, at best, but it was reporting a real view of the scene; it's call to fame is that it outputs real energy values in physical units (like energy per unit solid angle or luminance or such). But despite the cartoony models I provided, it did demonstrate subtleties that weren't hacks (needed for this application), things that you wouldn't think to or bother implementing directly. This? This grabs a lot of needed visual artifacts faster and more correctly without crazy hacks (or so it seems - it does say hybrid rendering).
13y ago

bobsgame 13y ago

I for one welcome our new PowerVR overlords.

mey 13y ago

Two thoughts: I would love to see a video of a dynamic environment (aka actors/objects moving in a scene). Also, how long before cryptocurrency miners use these to gain step function over current gpus.

duaneb 13y ago
> Also, how long before cryptocurrency miners use these to gain step function over current gpus. I can't imagine these ever being cheaper than ASICs.
lucian1900 13y ago
> Also, how long before cryptocurrency miners use these to gain step function over current gpus. Ugh. Never. Computing a hash won't be any faster on these GPUs.

deleted 13y ago

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herokusaki 13y ago

Would be fun if this relegated traditional GPUs to being used only for mining cryptocurrency.

bhouston 13y ago

Interactive raytracing is the future both in mobile and desktop. My project http://clara.io http://clara.io, an online 3D modeler + renderer, recently gained the ability to do embeded interactive ray traced 3D embeds using V-Ray (one of the best and most accurate renderers in the world). It works best on Chrome, Firefox and Safari: https://plus.google.com/u/0/+BenHouston3D/posts/DYq2RKJENC5 https://plus.google.com/u/0/+BenHouston3D/posts/DYq2RKJENC5 Here is another example: https://twitter.com/exocortexcom/status/443538733661704192 https://twitter.com/exocortexcom/status/443538733661704192 I can only see raytracing becoming more popular.

s-macke 13y ago
That's really great. Did you use emscripten or is the renderer programmed in Javascript?
- ddorian43 13y ago
  its not rendered on the frontend, but in the cloud (read the twitter responses)
- bhouston 13y ago
  It is cloud streaming, this is because we do not want to be limited by the CPU/memory capabilities of the client. V-Ray is an amazing renderer, but for complex scenes it can require +32GB and use up to 40 cores or even clusters of machines. We want to virtualize that infrastructure for our users.

eigenbom 13y ago

I'd wager that the current rasterising pipeline is more flexible than one based on raytracing - capable of generating a range of styles, not just photorealistic ones. And therefore having an extra dedicated chip for raytracing seems uneconomical. The comparison examples given in the article were slightly ridiculous. How does a non-reflective car represents 'traditional' rendering? Look at any great AAA game and you'll see reflections, refractions, radiosity, etc., that are all pretty amazing. I don't think that general demand will be there for alternative rendering hardware for quite a while.

banachtarski 13y ago
Those reflections and refractions and such rely on raytracing though so better ray-tracing hardware will help improve traditional pipelines as well (which are increasingly getting physically based). Also, there is nothing intrinsic about the rasterization pipeline that makes it more or less flexible that a ray-tracing one. In a physically based engine, I'd imagine you would be able to inject shader code on every bounce (for bump mapping, BRDF behavior, subsurface scattering, etc) as well as when the ray hits the lens. A good system would allow you to spawn more rays as need be or modify geometry like the current tesselation and geometry shaders. I think the important thing is that a physically based model would be amazing to work with from a graphics engineer perspective. No more crazy floating point hacks or occlusion tricks to get the desired effect. I'd rather the hacks be at the hardware level than the software level.
dualogy 13y ago
> I'd wager that the current rasterising pipeline is more flexible than one based on raytracing - capable of generating a range of styles, not just photorealistic ones Nope. I'd say the "raytracing pipeline" really does replace only the rasterization step, and once the triangle to draw is "found", you do whatever shading/lighting/fx/fragshader you want to draw it with? Wouldn't this be the most sensible approach? Rasterization in lay-man's terms really is just "figure out which triangle, if any, is 'hit' at this pixel", so a historically much faster and very neat hack to avoid the tracing of a ray.. But you don't get cheap soft-shadowing / ambient occlusion / reflect-refract and you'd need to do occlusion culling seperately for current-gen "complex" scenes to avoid a drawcall for all kinds of hidden objects. That's where at some point raytracing as it becomes more feasible also becomes much more attractive. Potentially also reducing geometry-LODing headaches etc..

leeoniya 13y ago

"life-like reflections"[1]? allow me to disagree. the reflection is too green. probably not the hardware's fault, or is it? [1] http://blog.imgtec.com/wp-content/uploads/2014/03/5_-PowerVR-Ray-Tracing-hybrid-rendering-1.jpg http://blog.imgtec.com/wp-content/uploads/2014/03/5_-PowerVR...

leeoniya 13y ago
hmm, looks better now on desktop than on phone

PhasmaFelis 13y ago

"... the potential that these technologies have to revolutionize the user experience from mobile and console gaming to virtual and augmented reality." I've been interested in ray-tracing since the early '90s, and I'm glad it's finally coming to real-time, but this isn't going to "revolutionize" shit. It's going to make 3D games and VR slightly prettier than they were. It's not going to enable new styles of gameplay or new modes of interaction. We will never again see anything like the enormous forward leaps in realtime graphics that happened during the '90s. I'm also a bit put off by their comparison showing that PowerVR has better reflections, shadows, and transparency than a raster engine with reflections and some shadows turned off and a very poor choice of glass-transparency filter. On another look, I don't even know what they're going for with the shadows. The rasterized image has "NO SHADOWS" printed right between the shadows of a building and a telephone wire, and their hybrid render has the light from the diner windows casting shadows across outside pavement in broad daylight. Bwuh?

jbverschoor 13y ago

The biggest problem here is content.. Producing content is the most expensive aspect of a game. Improvement in tooling and reuse are the only way we can actually properly use better rendering

zurn 13y ago
Wouldn't ray tracing make content production easier, needing fewer tricks to fake behaviour of light and shadow?

ilaksh 13y ago

I think the sample frames demonstrate that hybrid ray tracing is less realistic that pure path tracing. I hope that someone figures out how to make stuff like the Brigade 3 demos based just on feeding geometry and textures to hardware.

deleted 13y ago
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Kiro 13y ago

I thought Wolfenstein 3D was an example of ray tracing but reading this article and Wikipedia it seems to be all about lighting effects. What do I misunderstand?

faddotio 13y ago
I think you're thinking of raycasting.
din-9 13y ago
It was an example of ray casting and not ray tracing.

zurn 13y ago

Interesting to see if they can sell this, as ~everyone is invested in doing OpenGL. Maybe if Apple put it in all their iOS devices...

ohwp 13y ago

I think the examples used are not very impressive. And I think path tracing (which is a kind of ray tracing) is more interesting for the future. A nice blog about real time path tracing is: http://raytracey.blogspot.nl/ http://raytracey.blogspot.nl/

stcredzero 13y ago

high-performance ray tracing, graphics and compute in a power envelope suitable for mobile and embedded use cases. If true, color me impressed!

zokier 13y ago

So what is the API and libraries like? Is there any sort of built-in OGL fallback or do devs need to write two completely different renderers? Is there standards relating to this; are any other vendors going to be implementing same API? Is this new hardware compatible with the older Caustic2 cards?

bond 13y ago

This brings back some memories. Used to do some experiments using POV Ray back in the day. I remember how slow the process was, it could take several hours/days to generate an image full of reflections, but in the end the results were usually stunning... Link: http://www.povray.org/ http://www.povray.org/

beagle3 13y ago
Oh, the memories ... Before it was renamed "povray", it was called "dkbtrace". I printed the entire dkbtrace source and studied it, to see how a real Ray Tracer worked; and through it, I learned how efficient vtbls work (it was 1990 C, and though C++ was already starting to become visible and popular, it was still "that new language that may or may not become popular" - dkbtrace implemented all the OO inside). Thanks, D.K.B.

r4pha 13y ago

It never fails to amaze me how powerful raytracing is. Last year I took an "Image Synthesis" class and did a quick presentation about a post I've seen here on HN about a raytracker in 1337 bytes [0]. It is amazing how such a small program can generate an image with depth of view, shadows and texture. 0: http://fabiensanglard.net/rayTracing_back_of_business_card/index.php http://fabiensanglard.net/rayTracing_back_of_business_card/i...

touristtam 13y ago
Thanks I completely forgot about that one. :)

Geee 13y ago

This is incredible! Mobile GPU does 300 million rays per second without using any shading GFLOPS? This is the GPU that is going to be on the next iPhone, right? Brigade 3 does 750 million rays per second on Nvidia GTX 580 with full power. I just wonder what this thing could do when scaled up.

touristtam 13y ago

is this not from the same guys? https://www.youtube.com/watch?v=rfgz90Y93c0 https://www.youtube.com/watch?v=rfgz90Y93c0 < google tech talk