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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

#71

Post by leoc »

klodolph wrote: post #11
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…

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…

See my other comment https://news.ycombinator.com/item?id=7427486 .

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

#72

Post by leoc »

doktrin wrote: post #40
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…

> If raytraced scenes were hard to control, why would every single animated movie be raytraced? That's a bit of a stretch. Pixar didn't use ray-tracing until Cars [2006]. Even then, it was only applied for secondary effects. It wasn't until Monsters University [2013] that they produced the majority of a movie using ray-tracing [1]. That's a recent development, IMHO. [1] http://thisanimatedlife.blogspot.com/2013/05/pi…

Pixar were late holdouts against non-physically-based rendering though, apparently: https://www.youtube.com/watch?v=MG4QuTe8aUw#t=4410

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

#73

Post by tinco »

chrisseaton wrote: post #29
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…

"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.

You are absolutely right. People should stop upvoting my post because I'm totally wrong. Not only was Cars the first movie that was done using ray tracing, they thought it was glitchy and MU which was released 6 years later was actually the first movie to be fully raytraced.

That said, the technique they did use was scanline rendering, which is still rather different from z-buffering, which is the way GPU's generally render.

Of course now I'll change my argument that Pixar is after a non-realistic cartoony feel, so that gives them more freedom.

If you look at live action movies, the CG parts in there are either painted or ray traced, they need absolute control to be able to blend them.

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

#74

Post by ddorian43 »

s-macke wrote: post #49
bhouston wrote: post #26

Interactive raytracing is the future both in mobile and desktop. My project 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 Here is another example: https://twitter.…

That's really great. Did you use emscripten or is the renderer programmed in Javascript?

its not rendered on the frontend, but in the cloud (read the twitter responses)

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

#75

Post by berkut »

tinco wrote: post #73
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.

You are absolutely right. People should stop upvoting my post because I'm totally wrong. Not only was Cars the first movie that was done using ray tracing, they thought it was glitchy and MU which was released 6 years later was actually the first movie to be fully raytraced. That said, the technique they did use was scanline rendering, which is still rather different from z-buffering, which is the way GPU's generally…

That's Pixar - they've been late to the path tracing party by several years. Also MU didn't use raytracing for hair shadows - they still used deep shadow maps for that.

Other studios like ILM, SPI and Bluesky have been using full path tracing for years.

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

#76

Post by berkut »

chrisseaton wrote: post #29
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…

"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 other studios.

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

#77

Post by bhouston »

s-macke wrote: post #49
bhouston wrote: post #26

Interactive raytracing is the future both in mobile and desktop. My project 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 Here is another example: https://twitter.…

That's really great. Did you use emscripten or is the renderer programmed in Javascript?

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.

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

#78

Post by exDM69 »

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.

> 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 future we will have some kind of hardware acceleration for raytracing along with traditional triangle rasterization and they will be used together.

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

#79

Post by bond »

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/

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

#80

Post by sharpneli »

InclinedPlane wrote: post #12
higherpurpose wrote: post #6

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

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 s…

This might be bit of a tangent but this is one of the problems where it matters which parameter you are looking for.

While it is a O(n!) in relation to reflections a real physical rendering is 'mere' O(n) in relation to volume (or n^3 in relation to the sides of the cubic volume we want to simulate)! Why? We simply create a grid of around 200nm volumes and run a wave simulation for the light. Or O(nlogn) if we want to use fft based simulation.

Naturally this consumes horrendous amounts of memory and computational power simply because the size of spaces humans are interested in are so massive compared to wavelength of light.

But eventually we might move into this direction, maybe we even live to see it eventually.

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