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

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

#81

Post by chongli »

fidotron wrote: post #3

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 rasteris…

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.

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

#83

Post by chongli »

leoc wrote: post #70
tinco wrote: post #16

Earlier quoted context omitted.

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 scen…

John Carmack confirmed what fidotron said in the Quakecon 2012 talk which I stumbled across in the comments here recently: https://www.youtube.com/watch?v=MG4QuTe8aUw : he talks about ID artists referring to light-map dinking as "painting with light" and generally being reluctant to give up direct control of final appearances. Likely you're both right, and while it's harder to learn how to dink scenes and assets with…

an artist who has already mastered the black arts of tweaking everything just so is going to resent losing that control and having to let the physics take over.

Which in the long run is good for gamers. The industry obsession with pre-baked rendering passes is holding back games on an interactivity level.

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

#84

Post by beagle3 »

bond wrote: post #79

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/

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.

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

#85

Post by r4pha »

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/i...

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

#86

Post by Narishma »

jjoonathan wrote: post #18
mjcohenw wrote: post #5

How about FP64?

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.

Wat. They don't make gaming cards nor scientific cards. They make GPUs that go into iPhones and iPads.

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

#87

Post by gfodor »

exDM69 wrote: post #78
gfodor wrote: post #31

Earlier quoted context omitted.

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.

> Raster will die in the long run, it's pretty obvious. Care to elaborate why you think this is the case? Even when doing raytracing, the fastest way to do the first pass is to rasterize your triangles and output hit data to textures (similarly to deferred rendering). Additionally, triangle rasterizerization can be used for vector graphics, etc while raytracing is inherently only for 3d content. I think that in the f…

In the long run graphics will probably converge on an approach that properly estimates the rendering equation. That's why I think ray tracing ultimately will be the preferred solution.

(I'm talking on a extremely long timeline)

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

#88

Post by pjmlp »

berkut wrote: post #76
chrisseaton wrote: post #29

Earlier quoted context omitted.

"If raytraced scenes were hard to control, why would every single animated movie be ray traced?" I'm not entirely sure that's actually true. In this paper ( http://graphics.pixar.com/library/RayTracingCars/paper.pdf ) Pixar talk about how the first movie they even tested using ray tracing on was Cars. Before that they were using scanline rendering.

That's Pixar - they're behind the curve, and PRMan 17 and 18 (their commercial renderer they sell) has been pretty poor at full raytracing (monte-carlo integration) due to poor acceleration structures and the overhead of their RSL shading language. PRMan 19 looks like it's going to fix these issues to some degree. Other renderers like Arnold and VRay (full raytracers) have been being used for the last 5 years by othe…

Funny to see Pixar getting behind. I remember when I was amazed what Renderman could do in NeXT stations.

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

#89

Post by Geee »

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.

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

#90

Post by dragonwriter »

gfodor wrote: post #31
duaneb wrote: post #22

Earlier quoted context omitted.

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…

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.

> Sampled raytracing is the most natural approach to indirect lighting

Its been a while (~15 years or so) since I looked very deeply into this, but at that time I thought that radiosity was notably superior to raytracing for indirect lighting, and everyone and their cousin seemed to be doing hybrid ray tracing/radiosity systems for realistic rendering.

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