Interview with Chris Nichols of Digital Domain(Lighting Lead on TRON Legacy)

Interview with Chris Nichols of Digital Domain
(Lighting Lead on TRON Legacy)

By Jeff Mottle


CGarchitect Spoke with Chris Nichols (http://www.redeyetales.com), Lighting Lead at Digital Domain on TRON:Legacy. Chris' background is in architecture although he has been working in the VFX field for a number of years. Movies in his credit include I, Robot, The Day After Tomorrow, Stealth and Ghost Rider.

CGA: Did you guys work on any of the architecture at all in those shots?

Chris Nichols: Well no, not directly. So basically Disney had an art department as you probably know, who does a lot of the design work. But especially for me, the most unique part of it was that we actually worked very closely with the art department, to the point where they were actually within Digital Domain; working directly with the artists and collaborating directly with the artists, which I've never seen that happen to that level.

And the designers actually worked in CG as well, which usually we get mostly drawing, hand-drawing, stuff of that nature. But they actually worked with real models, and there was actual exchange of data between art department and Digital Domain more than I've ever seen.


Concept Art ©Disney Enterprises, Inc. All Rights Reserved.

CGA: Yeah, Joe (Director of Tron: Legacy) had mentioned that there was a lot of actual scale models that were done for this. Did you guys get your hands on those at all?

Chris Nichols: The physical models?

CGA: Yeah.

Chris Nichols: Well, we had a couple things here. We had some helmets here and a couple other things like that, but the light bike itself – no, we didn't have the light bike or anything of that nature. But I think usually props, sometimes we get access to props. Props are usually things that are handled by an actor, so a helmet, disc, things of that nature; baton, sometimes we'll get those. But physical models, I think they did build a full-scale light bike, for the publicity thing.

CGA: Right, not for shooting the movie.

Chris Nichols: No, no. They built it after we had finished it. So the light bike only existed in CG until they decided they needed to build one.

CGA: Yeah, I think Joe was talking a lot about the sets and whatnot, how the actual sets were all built as scale models in advance.

Chris Nichols: A lot of set pieces, like I think all of Flynn's house was built. And yeah, the End of the Line Club was all built, and the throne room in the ship was built; but the whole stadium was all CG, all the stadiums were all CG – the disc game. Obviously you can tell from the movie that a lot of it was all CG.

But yeah, it was actually quite nice to be that close to the designers. David Levy was here for a while and was working with us. And we would be able to go and make something and then hand it to David, and David would just reapply some touches to it and we would get it back and readjust it. So this was happening – it was a kind of "live design" process.

So that was a nice thing to work very directly with them, and in fact I got a nice email today from Ben Procter, who was one of the lead designers on a lot of the city stuff, and he was complimenting our work and was very happy about it. Like I said, I've never worked this closely with an art department, and I think it comes naturally from Joe (Kosinski). Joe is such a digital person that he works so well with additional mindset team, all the way from art department to CG, etc.
 

Concept Art ©Disney Enterprises, Inc. All Rights Reserved.

CGA: So enlighten me – what parts of the film did you work on specifically? And did DD as a whole work on anything else?

Chris Nichols: Well, I started off working on the environments team and was doing some setup for cityscape, but because of my involvement with and previous work with car commercials I ended up helping a lot with the light bike sequence, and then ended up taking over as the lighting lead for the light bike sequence. So I worked on the light bike sequence for well over a year, and we were just looking that up – it was about 152 shots for the light bike sequence.

CGA: Wow.

Chris Nichols: And after I did that I also helped out with another sequence that was done in collaboration with one of our outsource vendors, which was the big Rectifier sequence – the big interior space with all of the stuff inside of it. And my light bike team worked on a few shots within there as well.

CGA: You said you worked quite closely with the art department, but how involved could you get in terms of the overall mood and lighting of the film in terms of the direction that came from Joe?

Chris Nichols: Yeah, that was mainly driven by Joe and the art department, and Eric as well. Eric Barba, who was the Visual Effects Supervisor, really kind of tried to set the mood as much as possible based on the artwork. So Eric would take the artwork and interpret how he would want that to be represented in CG. So we would respond most directly to Eric in terms of how he wanted it to look.


Concept Art ©Disney Enterprises, Inc. All Rights Reserved.

The mood was obviously set up through the references of artwork that we had, and we had a ton of references of artwork on this show, so we were very well set in terms of how we wanted it to look. But it was basically very unusual in terms of how to light this world, because obviously as you can probably see there is no sun or moon but there is a lot of lighting and some other way to make the set work. So it was a little bit more challenging to find the inspiration of where the light source or key is in that particular portion.

CGA: How did you actually go about lighting a scene that for the most part is self-illuminated? Or did a lot of light come from self-illumination?

Chris Nichols: Well, we had a lot of ideas. It took us awhile to come up with the best methodology, and what we do is we actually have a lot of lights that are hitting the bikes and the riders that are not actually visible on-set. And those (are done) in the very same way that you would do a car commercial, where you'd have a car going through a light source and then you just paint out the light if it happens to be visible in camera; because something black and shiny needs to travel through a light source, and it can't be a point light of any kind – it has to be a big, large area light.

So we had a special area light that we designed that would look like a standard car commercial area light, and we made them look more techy, more Tron-like. And we painted them the way we wanted them to look like, and we called them "Trino Flos," which is kind of a take-off on Kino Flo lights but more Tron-like, so we called them Trino Flos.


Film Frame Garrett Hedlund ©Disney Enterprises, Inc. All Rights Reserved.

And so if you look, as the bikes travel through you'll notice this "whoosh-whoosh, whoosh-whoosh," kind of light traveling through them, and those were sort of designed as part of the light kit. And then also the stadium itself has a huge band of stadium lights around the periphery, which also provide some good environmental lighting to the whole scene.

CGA: Being that the film was intended for 3D, are there any special considerations that you have to take into account when you light scenes like that?

Chris Nichols: Lighting in terms of 3D? Well, yeah. I mean reflections are very key in 3D, because a reflection of something that's on a flat surface will have just as much 3D-ness as it would be if it were not reflecting. Reflections are basically as stereoscopic as anything else, but as that surface starts to curve it becomes more of a fisheye and your stereo effect starts to go away.

So it's kind of an interesting issue, as well as how things travel through things – refractions and distorted refractions through stereo start to look pretty interesting. It's the same thing; if you do it accurately and you retrace everything correctly, and you use your proper stereo settings it should all kind of work together.

So the film was set up as a stereo show from the very, very beginning. They used true stereoscopic cameras so there was no conversion that was done. All of the previz was done in stereo so that we knew exactly where and how we would want to set up our cameras. And then all of the actual tracking was done in stereo, all the roto was done in stereo, I mean all of that.

So it was a real stereo-stereo show, which made it very strict and by the rules in terms of how everything was made. I'm working on a non-stereo show right now and it's interesting how much more you can get away with on a 2D than you can a 3D. And 3D, you can't get away as much especially in compositing – you kind of have to render both eyes. And I think it shows. Things look very, very keen and clean in stereo in Tron in a lot of ways.


Concept Art ©Disney Enterprises, Inc. All Rights Reserved.

CGA: What was one of the most challenging aspects of working on this film?

Chris Nichols: Well, it's a very shiny world. You've got a lot of high-contrast stuff and clean surfaces, so you can't really hide a lot in terms of what's going on in the computer. Stereo was a huge challenge as well because sometimes we'd have to light it and then adjust it for stereo in case something didn't work. But by the end we actually had a really solid stereo pipeline where we would get everything approved in 2D, and then once we got it approved we could just render the other eye and just comp it in 3D. And as everything, in the beginning it was very rough and by the end it was smooth to do the stereo.

CGA: Gotcha. With so much glass in this film, how did that impact lighting and setting up the scenes, and even render times with that?

Chris Nichols: That was probably the hardest thing for the light bike sequence. No, there's two hard things with the light bike sequence: one was the amount of glass and how reflections worked, which we had it pretty well figured out by the end. But again, figuring that out was a real challenge. I remember specifically our first under lower-level shot that we worked on, where we obviously have a glass ceiling and a glass floor, I had set up a render with four bounces of reflection and it was just too much. Visually speaking it was too much to look at, and so it was basically (like) we were in a big house of mirrors.

So it was even Joe's call – he said "That looks way too busy, I can't see that." So we dialed back the reflection filters so they would dim out as they would get to the next bounce quite a bit, as well as just pretty much cutting them off so it wouldn't be too confusing to the view. So that was a hard part.


Film Frame ©Disney Enterprises, Inc. All Rights Reserved.

The other challenging part was once we started to go towards the lower levels, because we had a level of tinting to the glass it would start to get really dark. So what we came up with was that the gridlines, which were the squares, would start to become really bright on the ceiling to become a light source. So speaking from an architecture point of view, it was a lot more like travelling through a parking garage or an office building where you had these rings of light above everything.

And once we had those dialed in it actually added quite a bit of richness to the under-the-glass shot, which we were challenged (by) at first because everything got so dim. So once we figured out how to create extra light sources on the lower levels it worked out quite nicely to have the architecture become a light source again.

CGA: Were there any new techniques or technologies that you guys pioneered for this film specifically? I know Joe had mentioned that they had done a number of things on the filming side.

Chris Nichols: Yeah, we did. Obviously there was a lot of stuff on the heads, which I wasn't necessarily a part of, which was an evolution of Benjamin Buttons pipeline. But there was a lot of innovative stuff that we had come up (with) on top of that.

I was thinking about this question, and what I thought was really interesting artistically speaking was how we did some of the stereo things that people have said "Don't do this in stereo" but ended up being quite nice. An example is they always say don't make a shallow depth of field in stereo because things out of focus are confusing in stereo, but Joe insisted on using very, very fat lenses – I think it was F1.3 for a lot of the shots. And he did that so he could get as much natural lighting and not have any extra lighting sources on the actors so that their suits could light up really nicely.

But by doing that, obviously your depth of field becomes very, very shallow, and there was this concern that it would not work in stereo. But I believe it actually worked really, really well.


Concept Art ©Disney Enterprises, Inc. All Rights Reserved.

The other thing that you're also told to avoid constantly in stereo are things like lens flares and any kind of lens pollution, but what the compositing team did is they came up with a really good way of making lens flares or any kind of lens effect work in stereo. And they did that by actually layering all of the flares in 3D space as well, so they weren't just flat on the screen – they actually sort of had this perfect marriage of working within the 3D space, and they had a really innovative way of doing that.

So I think in terms of the way stereo works and the way that is, we did two major things that people say never do, which I think worked out way more successfully than we ever thought they would. I was really impressed with the way they worked out that effect, so that was a nice and refreshing thing to work with as well.

CGA: You mentioned that Joe had provided you some guidance on some of the things, like the reflections. How closely were you able to work with him throughout the whole process?

Chris Nichols: Well me personally, not that close. I mean we've known each other, as you know, because of our architecture background so we would say hi to each other when we saw each other. But there were over 800 people that worked on Tron just for visual effects, so Joe, he really only worked directly with Eric Barba. So Eric and he would make decisions on how visual effects would work, and then we would work with Eric in terms of how he would want to interpret what he wanted out of his responses from Joe.

So we would always be present when Joe would be making comments on the work that we were doing, but we would execute it based on our interpretation of what Joe wanted; and since he was really speaking to Eric we would basically work directly with Eric on that. So I didn't have a direct line of communication with Joe but we were definitely present in hearing how he communicated his ideas.

CGA: Obviously your background is in architecture, and Joe's is in architecture as well. And Joe had mentioned brining in a lot of people from outside traditional visual effects fields and film fields – did the same thing happen within DD when you guys worked on this?

Chris Nichols: Well, visual effects is naturally a hodgepodge of people. There's a lot of ex-architects, a lot of artists, programmers – people from all kinds of fields come together to work on it. I'd say that it's just sort of par for the course. And it wasn't until really five or six years ago that there was a degree in visual effects that you could get, so most of the people that showed up before that – which is a majority of them – have degrees in all sorts of things.

So that's kind of already the nature of what the industry is about, which I think is very refreshing. Obviously you have to have a variety of different aesthetics and feeling before you go into visual effects. A modeler is not going to be the same thing as an animator; I mean I look at what animators do and there's no way I feel like I could do anything of what an animator does, and I'm sure certain animators feel that they couldn't do lighting or compositing at all. I mean they are very, very different fields, so I think that because of that you have to come from different backgrounds.


Film Frame Garrett Hedlund ©Disney Enterprises, Inc. All Rights Reserved.

CGA: So was anything done down there in LA or did you guys also have a studio up in Vancouver?

Chris Nichols: We had a studio in Vancouver, and basically we did about 882 shots total; 723 were in Venice, and 159 were done in Vancouver. And I think overall Digital Domain was responsible for all of the visual effects including all of the outsourcing, so I think overall visual effects shots was 1,575 shots.

CGA: Wow! How long were you guys working on this?

Chris Nichols: Well, that's an interesting question because I don't know if you know the story, but DD was involved before it was even a movie, before it was even greenlit. And in fact, DD helped that process along by working with Joe on doing a first concept artwork, which was in 2006.

CGA: Is that the video that he has on his website that's the original pitch film?

Chris Nichols: It was started at the end of 2007, and then it was finished in the summer of '08. It went through a revolution, because it was only 30 seconds but it eventually grew to 3 minutes. And so the final version that you see was done in July of '08, and then they showed it at Comic-Con that year.

So DD had an involvement in that project since 2007, so that would be three years, but when it actually got greenlit was probably about two years. So that's basically when it started up, and I came in on the project and was on it for about a year and a half or so.

CGA: Were you guys working exclusively on this film, or can you even bring on other project when you're working on something of this scale?

Chris Nichols: No. The company had other projects, Digital Domain definitely had other projects going on at the same time. Our Commercial Department was still making commercials, and we had two or three other features being done, not to the scale of Tron while Tron was going on. Tron was probably the biggest show that DD had done at that time.

CGA: Tron was.

Chris Nichols: Tron, yeah. When I was booked on Tron I was booked on Tron, and that was all I worked on.



Film Frame Garrett Hedlund ©Disney Enterprises, Inc. All Rights Reserved.

CGA: Was this the most complex or ambitious project you've worked on in visual effects?

Chris Nichols: Yeah, I would say it definitely was the largest project I worked on, because of 152 shots, 90% of it was all CG. We had obviously a few shots of characters which were incorporated in, as well as we had a system for the faces inside the helmets. Those were actually projected from multiple cameras, so we had a special tracking method that would basically project the plate back onto a CG head and then refract it through the helmet.

So that was essentially all CG, even though the actor was really there, because we didn't have to give anything to compositing. Compositing didn't take something from a plate and put it in; they took our element, which was reprojection of the head, back in.

CGA: What was the most difficult shot that you worked on in the film and what was your favorite shot?

Chris Nichols: Well, I think they're almost the same. The most difficult shots – I mentioned the glass was very challenging but the hard parts were some of the derezzing and uprezzing. Most of those effects were generated in Houdini and they basically generated huge amounts of data, and we had to create a system to be able to read all of that data for rendering. So those became really, really complex and hard to incorporate and figure out.

Also we basically had to coordinate really closely with the animation team to get all the timing correct, coordinate really closely with the effects team to get all the data given across to us, and then coordinate really closely with the compositing team to make sure all of the layers and holdouts were all set up correctly. And so the two big uprezzing shots – which were Sam uprezzing onto his bike, as well as Clu uprezzing onto his bike – didn't really get finished until pretty much the end. Those were extremely challenging to do.

The derezzing shots were pretty challenging at the beginning but then we had it very well figured out towards the end. But those were more fun than they were challenging by the end because there was just so much stuff going on – it was a lot of fun to just see these bikes explode into millions of pieces. But the uprezzing and the coordination of how all of that worked became very much a challenge.


Film Frame ©Disney Enterprises, Inc. All Rights Reserved.

I'd say that the uprezzing of Sam was kind of an interesting thing because we had to time it because there was a live action plate of Sam running, and we had to incorporate him to go into a CG Sam as he transforms into the bike. But it was extremely hard to get the suits to match exactly because of the glow lines; you could never get the folds to be exactly the right way and everything. So what we did is we actually had a complete CG Sam except for the head, but that matches as much as possible all the muscle jiggle and all of that effect of Sam. So it was exactly a rotomation of his motion and then his head was added on top, so that the transition as he jumps on the bike is completely seamless.

CGA: What kind of software were you using in your pipeline? Is it all in-house stuff or did you use things like V-Ray, or can you talk about that?

Chris Nichols: I'm not sure I can talk about it, but we have obviously a lot of in-house software that we use for some of our stuff. You can go ahead and tell him, Tim.

Tim: You mentioned Houdini, Maya, NUKE for compositing.

CGA: Was V-Ray used at all?

Tim: Yeah, yeah. Also mental ray.

Chris Nichols: We have our own tracking software, which was key especially for stereo work. Storm is our own in-house volumetric vendor that we use for a lot of the clouds and some of the atmospheric effects; and then we also have a lot of our animation tools, especially for the facial reconstruction, are all in-house tools. And most of our tools are highly, highly tweaked for our own purposes.

Tim: So even the off-the-shelf ones aren't off the shelf.

Chris Nichols: Yeah. I mean Maya DD is not Maya that you'd buy at the store. We have a big team of technical directors that write a bunch of tools for us for most things, and we have our own rendering layer system that we developed in-house. So yeah, we had our own rendered layering system for all of our layers and all of our submissions, and it's basically highly tweaked to work in-house. So when you say "in-house," while you do use off-the-shelf software it's never really utilized in the same way.

CGA: Gotcha. So is there any one rendering system that was used as the core to render most of your work, or is it kind of a mix of everything?

Chris Nichols: It was a mix of everything. Most of the stuff, obviously V-Ray was used but also mental ray was heavily used – for example, the heads were very much relying on that.

CGA: There were obviously so many shots, I know Joe mentioned that he had to in the end cut some stuff out that he wanted but in the end just couldn't fit it in. Are there shots in visual effects that you guys worked on that got cut from the final film?

Chris Nichols: Speaking from memory, not on my sequence that much because the previz was pretty well cut and timed out really well. I've worked on other shows where a whole sequence gets cut, and it's very depressing for some of the artists because they've worked on it for months and months and then they just cut the whole sequence out. But not so much this one that I can think of, specifically on the work that I had done. I'm not sure of any big sequences that Joe was speaking of that actually got cut because it seemed like the edit was pretty tight.

CGA: It might have been some stuff earlier on maybe.

Chris Nichols: It could have been. It could have been some of the sequences that were not actually incorporated.

CGA: So what's next for you?

Chris Nichols: I'm working on another show right now that I'm doing some lighting on. It's a show called Real Steel. I can't tell you really much more beyond its title but I'm sure you can look it up if you need to.

Tim: There's a trailer for it. I'm sure if you find the trailer you'll get the idea.

CGA: Okay. One of the questions I'd not asked earlier, Chris, you told me years ago that you did more real architecture and design in visual effects than you ever did working in architecture. Does that still hold true for a lot of the films that you're working on? Certainly Tron was pretty heavy in architecture.

Chris Nichols: Yeah. It's become a little bit more natural to me, but looking back at how I did architecture I do feel that you have definitely more leeway in architecture in terms of design working in visual effects; I would say a little less so on this film because so much was designed. I mean the design team designed doorknobs, everything. Everything was designed at some level.

So usually when I say that I have the opportunity to design is because they haven't quite figured it out, so they'll look at someone and say "Hey, you can design something – why don't you do that?" And I definitely had that opportunity to do some of that here but much less so because everything was really, really thought out to such a level.

But in terms of contrast levels, the way that the glass looks and feels and the shading on the glass – it wasn't figured out anything more than "it's glass," but does it have any breakup to it? It may have smudges, it may have this distortion and wobble. We went through many iterations together with Eric on how that looks so I definitely still had some contribution in terms of how that works.

And I absolutely do think that I have more opportunity to design in visual effects than architecture because I have a background as a designer as opposed to having a background as a CG person when I go into architecture. When I'm in architecture, all they want to use me for is my CG skills, but I have the opportunity to actually work a little bit on my design as well. So it's kind of nice to have that opportunity.

CGA: Cool. You mentioned that you had a whole bunch of stats there. Is there anything that didn't get culled out that might be noteworthy or worth mentioning?

Chris Nichols: Let me see… Over 720,000 man hours were used on Tron just at DD. 800 people worked on it across all the facilities. We used over 1 petabyte of space but we kept online at any one point in time only about 175 terabytes because we didn't really have that much space to work with at any one time. We also had over 6000 cores that we used for rendering, so quite a bit of rendering was done.

CGA: Is that much hardware and server firms on site all the time, or do you bring those in on a per-project basis?

Chris Nichols: It fluctuates. Keep in mind, some of that was rendered over in Vancouver and they had a much smaller rendering farm at the time; a smaller but more powerful rendering farm. By the end we had renderings scattered all over the building – it was quite funny. So yeah, we bring in racks and racks of servers, and that's not uncommon when you ramp up. You don't want to necessarily have a bunch of cores that are sitting around not doing anything, so you only want to bring in extra horsepower when you really need it.