Discussion topic: Is scanline rendering becoming obsolete?

[playmesumch00ns]

Until there exist raytracing algorithms for doing 3d motion blur and sub-pixel displacement for no extra rendering cost, or until we get processors so fast that the extra cost doesn't matter any more, scanline (by this I mean REYES) rendering is going to be essential for vfx production at least.

[soulburn3d]

Each different type of renderer is fast at doing different things. So no, I don't think any particular type of render algorithm is gonna die anytime soon. Some will become less popular, like right now a lot of people need raytracing so raytracing is in vogue, but scanline or reyes based renderers will never go away.

- Neil

[Wes_Brown]

Well, I guess I should have been more specific in my title! :)

I'll try and get a little closer to what I meant to say because I know scanline will never TRULY go away. I guess what I meant was: For fully animated movies, is scanline rendering going the way of the dodo because of the realism offered in more advanced methods? Is it a fad or a permanant shift?

For instance, I don't think pre-incredibles, Pixar used any kind of GI methods. (Though I could be wrong there for sure and feel free to correct me on that if I am.) Cars looked almost entirely rendered that way. Same with over the hedge and of course blue-sky's awesome cg studio software and the Ice Age movies. I don't know if this is a temporary trend or a move towards the permanant future. For sure, I think it will be more standard from now on because it is easier to do than it used to be. For instance, in one of Jeremy Birn's lighting challenges (the bottles), I don't think I saw one entry that did not use GI or HDRI or something. Again, there is nothing wrong here and the renders were beautiful but I am seeing so few scanline or plain raytraced scenes anymore that I am starting to think younger cg artists will almost never try and light without it. I could be wrong but I remember when I taught at a school a few years ago and I would show the students my work, they though I used mental-ray/GI/HDRI because they did not realize what could be done with just a scanline render and some well placed lights.


Those young whipper-snappers! :)

[stew]

Maybe it's just because I'm reading GPU Gems 2 right now, but I wouldn't be surprised if we'd see more and more non-raytraced GI in production. While raytracing hasn't been seeping either (see OpenRT), modern vector and stream processing hardware (SSE, Altivec, GPUs) works more naturally with coherent algorithms. There are promising approaches to rasterization based GI (for example Parthenon (http://www.bee-www.com/parthenon/)) that might be ready for general application in a few months or years. IWithout having implemented it myself, my guess would be that rasterization based GI could also be extended to incorporate motion blur more easily than raytraced GI.

Regarding a general GI vs non-GI lighting: I think it's great that we now have resources and methods to use GI to replace many hand-placed bounce lights. But just like everything, use with caution: While it's a convenient way to a decent looking scene quickly, it doesn't take the art out of good lighting to tell a story or an emotion. And GI can sometimes be a real pain in the you know where - what if physics dictate a light reflection in a place where your art director absolutely doesn't want it?

[rendermaniac]

Most renderers used in production tend to be hybrid renderers. I think your question would better be rephrased as - "Is rendering without using GI going the way of the dodo?" - and in that regard you are probably correct.

Simon

[playmesumch00ns]

Yep reading your second post it seems that's what your're really asking. And I agree with Simon, GI and other raytracing techniques are here to stay.

[Wes_Brown]

Most renderers used in production tend to be hybrid renderers. I think your question would better be rephrased as - "Is rendering without using GI going the way of the dodo?" - and in that regard you are probably correct.

Simon

There ya go! :) That is exactly what I meant. I forgot that because renders ARE hyrbid, my quesiton was confusing.

[soulburn3d]

I guess what I meant was: For fully animated movies, is scanline rendering going the way of the dodo because of the realism offered in more adnavced methods? Is it a fad or a permanant shift?

I think it's a fad that will eventually disappear. The reason to do an animated feature in some part is to do a film that couldn't be done as a live action feature. If that's the case, then why try to make it look as photoreal as possible? Right now we have all these new tools that lets us make our work look more real, and movie studios are exploring those techniques, but there's a huge area to explore in NPR (non-photorealistic rendering). Just look at the 5 short animated films nominated in the oscars this year, several of them didn't look realistic at all, but were very stylized and very cool looking. And not every style requires stuff like reflections, GI, etc. So from a marketing perspective, a lot of animated fims are going the GI route right now, and so it's good to know that stuff, but I believe there will be an eventual backlash and people will try and go for more stylized looks, many of which won't need raytracing specifically, and so non-raytraced based renderers will always survive.

- Neil

[CupOWonton]

Standard Scaline Area Shadows = SLOWWWWWWWW
Mental Ray Area Shadows = Awsome!

[Wes_Brown]

I think it's a fad that will eventually disappear. The reason to do an animated feature in some part is to do a film that couldn't be done as a live action feature. If that's the case, then why try to make it look as photoreal as possible? Right now we have all these new tools that lets us make our work look more real, and movie studios are exploring those techniques, but there's a huge area to explore in NPR (non-photorealistic rendering). Just look at the 5 short animated films nominated in the oscars this year, several of them didn't look realistic at all, but were very stylized and very cool looking. And not every style requires stuff like reflections, GI, etc. So from a marketing perspective, a lot of animated fims are going the GI route right now, and so it's good to know that stuff, but I believe there will be an eventual backlash and people will try and go for more stylized looks, many of which won't need raytracing specifically, and so non-raytraced based renderers will always survive.

- Neil

Interesting point. Have you ever seen "fishing", the PDI short that came out in about 1999 or so? It looked like a watercolor and it was BEAUTIFUL. One thing I have noticed about cg movies recently: they all look the same! It is getting harder and harder to distinguish personal style any more.

[kary]

Interesting point. Have you ever seen "fishing", the PDI short that came out in about 1999 or so? It looked like a watercolor and it was BEAUTIFUL. One thig I have noticed about cg movies recently: they all look the same! It is getting harder and harder to distinguish personal style any more.

I missed that one, but it does make you think about what really stands out.

I think The Incredibles is the best thing is recent memory, and if I recall correctly that was straight lighting -- but the characters were sweetened with a bit of sub surface scattering? Then again everything worked rather well in that film, but the look stood on it's own -- Bob stopping the train early on, when they were captured etc all had support in stylized lighting.

On the other end of the technical spectrum Hoodwinked did extremely well, and that certainly wasn't driven by GI :).

Mind you both of those aren't examples from this summer, excuse if that point is irrelevant to the topic. Though it seems to be switching a bit more to GI resulting in a 'sameness' look (photorealisim) vs stylization.

[rendermaniac]

The incredibles had subsurface scattering and ambient occlusion. I think it may even have add some proper colour bleeding in it.

However GI isn't a lighting style, it is a lighting technique. You still need to place lights, set them to the right colours, play with falloff and gobos etc. GI just adds a bit more realism and give you a nice base to work from.

I suspect the best way of using GI is to have it baked out - and then be able to dial it in where necessary (probably in the comp).

Of course my view is coming from vfx where matching reality is more important.

Also I don't see any reason why GI couldn't be useful for NPR too - it is just more colour information.

Simon

[playmesumch00ns]

Absolutely agree with simon again: GI's just another tool in the box. Just cos you have a fancy GI rennderer doesn't make your pictures any more interesting (something a lot of people on the maxwell forum gallery have yet to learn).

Something that I think we'll see a lot more of in upcoming animated features is the miniature look, like replicating that feeling of everything being made out of small clay models, in which case GI becomes even more important than in photoreal rendering.

[soulburn3d]

One thing I have noticed about cg movies recently: they all look the same! It is getting harder and harder to distinguish personal style any more.

That's because when you spend $100 million on a film, you'll have a tough time convincing investors to try something different or experimental. Shrek made a bazillion dollars, so make all films look likt that!

Most of the more experimental stuff exists in the short films. Lorenzo being another fantastic example I saw recently of doing something different.

- Neil

[CupOWonton]

Why is it that the 3d movies copy the hell out of eachother?

AntZ, Bugs Life, Finding Nemo, Sharks Tale, The new Aardman film whos name escapes me, and Rattatoui?

Do they think no one notices?

[ChimpanG]

Why is it that the 3d movies copy the hell out of eachother?

AntZ, Bugs Life, Finding Nemo, Sharks Tale, The new Aardman film whos name escapes me, and Rattatoui?

Do they think no one notices?
"That's because when you spend $100 million on a film, you'll have a tough time convincing investors to try something different or experimental. Shrek made a bazillion dollars, so make all films look likt that!"

^that is why.

[kary]

Also I don't see any reason why GI couldn't be useful for NPR too - it is just more colour information.

I was thinking about that this morning and arrived there. I was caught up associating it with the styles of films that don't click for me -- some of the attempts at "uber realisitic skin" on full acting characters feels zombified to me. Whereas most creatures integrated into live action are extremely smooth now.

I suspect the best way of using GI is to have it baked out - and then be able to dial it in where necessary (probably in the comp).

Putting it that way really hammers home your point.

GLandolina, heh well placed quote ;)

[Wes_Brown]

That's because when you spend $100 million on a film, you'll have a tough time convincing investors to try something different or experimental. Shrek made a bazillion dollars, so make all films look likt that!

Most of the more experimental stuff exists in the short films. Lorenzo being another fantastic example I saw recently of doing something different.

- Neil

True. It is like the music industry that way I guess: with SOOO MUCH money on the line, people are afraid to take a gamble because they need to recoup that money. The sad thing is, they (the investors) might be right to a degree! Case in point: My friend saw a trailer for a 2d movie and it had some AWESOME animation in it. I mean really slow character full body turns...beautiful stuff. you know what he said? "It looks flat." He knows nothing about animation and did not really even realize the difference between 2d and 3d...he just knew it didn't look like the other movies out there. It hit me like a ton of bricks that there ARE people who are really put off by anything different... :(

I remember being really impressed with the watercolor backgrounds in Lilo and Stitch. I thought that was a nice departure. I also remember the painting effects in "what dreams may come." Nice!

I do love NPR and I would like to see a really big hit made with some really beautiful new technique. It would jazz things up a bit. :)

[jeremybirn]

I was thinking about that this morning and arrived there. I was caught up associating it with the styles of films that don't click for me -- some of the attempts at "uber realisitic skin" on full acting characters feels zombified to me.

Yeah, the "zombie" films you're complaining about didn't even use GI. The zombified look comes mostly from character design, modeling, and texturing being hyper-detailed representations of humans, while the animation, deformation, shading, and rendering doesn't all live-up to the behavior of a real person.

-jeremy

[jeremybirn]

Cars looked almost entirely rendered that way.
On behalf of all the people who carefully adjusted hundreds of little lights to add bounce and fill and colors to different parts of those shots, I'll thank you for saying it looked that way. :thumbsup:

For instance, in one of Jeremy Birn's lighting challenges (the bottles), I don't think I saw one entry that did not use GI or HDRI or something.
Most of those images used raytracing for reflections and refraction, and many of them used Caustics, but I don't know if I saw any that used GI for diffuse-diffuse interreflections at all. This doesn't surprise me - once you've got the expense of raytracing reflections and refractions through all those bottles, doing full GI for the diffuse bounce light as well would be positively masochistic.

I am seeing so few scanline or plain raytraced scenes anymore that I am starting to think younger cg artists will almost never try and light without it.
When you talk about "plain raytraced scenes" it almost sounds as if you're thinking of raytracing as a basic and GI as the optional extra. In animated features, raytracing and GI are both in the same boat as optional extras, things to be used selectively and in a controlled way, if aspects of them are used at all. A lot of other things are considered "basic needs": doing everything at high resolution with motion blur and camera-based depth of field can be a basic need for every frame in a movie, for example. But in that context, there's no such thing as "plain raytraced scenes." If some aspect of GI or raytracing are needed, then they will be set up selectively with regard for what needs to reflect (which objects, a low-res proxy of the objects, can you raytrace against a card with an image of the object instead of the object itself,), whether and how it can be baked, how and where the reflections appear, and how they are sampled. It's not like rendering a still of some bottles on a PC where you just turn on raytracing and any object just reflects any other objects in the scene whenever they show up, running the same shaders and using the same geometry and lights... if that's what you call a "plain raytraced scene" then that's not likely to be done for any complex scene in an animated feature.

-jeremy

[Wes_Brown]

On behalf of all the people who carefully adjusted hundreds of little lights to add bounce and fill and colors to different parts of those shots, I'll thank you for saying it looked that way. :thumbsup:


Most of those images used raytracing for reflections and refraction, and many of them used Caustics, but I don't know if I saw any that used GI for diffuse-diffuse interreflections at all. This doesn't surprise me - once you've got the expense of raytracing reflections and refractions through all those bottles, doing full GI for the diffuse bounce light as well would be positively masochistic.


When you talk about "plain raytraced scenes" it almost sounds as if you're thinking of raytracing as a basic and GI as the optional extra. In animated features, raytracing and GI are both in the same boat as optional extras, things to be used selectively and in a controlled way, if aspects of them are used at all. A lot of other things are considered "basic needs": doing everything at high resolution with motion blur and camera-based depth of field can be a basic need for every frame in a movie, for example. But in that context, there's no such thing as "plain raytraced scenes." If some aspect of GI or raytracing are needed, then they will be set up selectively with regard for what needs to reflect (which objects, a low-res proxy of the objects, can you raytrace against a card with an image of the object instead of the object itself,), whether and how it can be baked, how and where the reflections appear, and how they are sampled. It's not like rendering a still of some bottles on a PC where you just turn on raytracing and any object just reflects any other objects in the scene whenever they show up, running the same shaders and using the same geometry and lights... if that's what you call a "plain raytraced scene" then that's not likely to be done for any complex scene in an animated feature.

-jeremy

Hey Jeremy! :)Yeah, when I mean "plain raytraced scenes" I really should have said "Scenes without GI." I realize raytracing in general is very much an option in the feature film world and is used as sparingly as possible. Let's face it: 24 frames a second for 2 hours requires as speedy a render as possible and time ='s money! :)

As for "Cars", what percentage would you say was rendered with GI (or an equivalent technique) versus a ton of bounce lights? The neon scenes at night were REALLY mind-blowing! Yes: In looking at the film it looked as if the entire thing was GI so props to you guys for all the fill and bounce lights! I saw in the credits Jean Claude K had a part to play. I have talked to him before and he really knows his stuff. He introduced be to the "gradient lighting" that was used in monster's inc.

I will have to say that as far as technical and artistic points, the lighting and rendering were the parts of "Cars" that impressed me the most. But of course, since I am a lighting guy, that is what I really focused on.

I remember the first time I saw an HDRI rendering (Paul D's "rendering with natural light" at siggraph). I remember thinking: this is THE future of rendering to match on-set lighting to CG. Sigh... :( I miss siggraph. I haven't been able to attend since new Orleans in 2000 I think...

[Wes_Brown]

Yeah, the "zombie" films you're complaining about didn't even use GI. The zombified look comes mostly from character design, modeling, and texturing being hyper-detailed representations of humans, while the animation, deformation, shading, and rendering doesn't all live-up to the behavior of a real person.

-jeremy

This brings up a good point: Have any of you seen any realistically rendered CG humans that overcame the "uncanny valley?" If so, what was it? There were a few shots of the old man in "final fantasy" that came pretty darn close I think.

[jeremybirn]

That is a shame if you're not going to SIGGRAPH, Wes. Every year there are presentations from Pixar and other studios that go over these technologies, and a lot more information gets released than individual artists would be free to post in web discussions. I guess some of the papers end up on the web, and when the DVD comes out for Cars there will could be an interview with JC himself (the Director of Photography for the lighting) that might cover more about approaches.

On the "uncanny valley" thing, all the photoreal humans I've seen in movies that don't raise issues like that have been digitial doubles added as visual effects to live-action films. Obviously the fact that these can be brief shots, very closely based on a real actor, and are intercut with footage of the real actor for most of the performance, helps immensely there. In CG films, if you made a photoreal-looking character in terms of accurately digitizing a person's face, skin, getting realistic skin shading, etc., you could get still renders that looked like a photograph of a person, but then if you keyframe animated his face and body, that could be a jarring mix of styles.

-jeremy

[Wes_Brown]

That is a shame if you're not going to SIGGRAPH, Wes. Every year there are presentations from Pixar and other studios that go over these technologies, and a lot more information gets released than individual artists would be free to post in web discussions.

-jeremy

Sigh...:( I know. I LOVE siggraph. Every year thoug it seems either project deadlines or budget have prevented me from traveling. I'll get back soon though. I miss the emerging technologies and the art gallery!

Anyone remember the woodden mirror?! Awesome!

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