Oz the Great and Powerful CG

Oz the Great and the Powerful comes out on Blu-Ray next Monday, the 1st of July. To mark the film’s release, we recently spoke with VFX supervisor Scott Stokdyk. The interview started out  in the same way as most VFX artist interviews, discussing what’s real and what’s not, but as it went on we began to discuss digital reshoots, the use of the technology to alter performances in post, and the ethics of this sort of work,.

HeyUGuys: Could you clear up where the practical effects finished, and your job began?

Scott Stokdyk: We kind of try to hide it as much as possible. It’s interesting, because technically, sometimes it’s easier to replace a set entirely, so I’d have to go on a case-by-case basis.

How about then you give me an example, using the treasure room.

The typical rule of thumb is that we try to make the floor that they’re standing on, and if there’s the opportunity to make a wall or two, and have non-visual effects shots, we did. But basically, there was one platform and a hill of coins beyond it, and everything else was synthetic.

I actually want to give you a different example that’s maybe a better one: When they are first walking through the forest to meet the carriage procession that takes them into Oz. Originally when we shot that, we had the idea that they had found the Yellow Brick Road earlier. The story changed, and we ended up replacing everything in the scene except the people. We roto’d out the actors who were originally on the Yellow Brick Road, and basically put the carriage, which was on dirt, on the Yellow Brick Road. So we kind of swapped dirt and Yellow Brick Road.

Would that have been possible five or ten years ago?

It would have been possible, but it would have been incredibly hard, and people would have thought you were crazy to do it. Nowadays, it’s a tool in the toolbox, and when it serves the story – basically it helps the cut in this case, so there was never a second thought about doing it.

I assume that sort of VFX work has replaced reshooting to some degree

You do go in knowing that you can go and shape the movie more in post because of these tools. To that extent, whatever pieces of the set we had, we always shot clean plates. Anything you’re shooting with an actor on the set, you walk the actor out and reshoot it, knowing that if you do need to change the dialogue, or write a piece later, you shoot an actor against blue screen and put them over the clean plate. Sometimes you just do a CG background over the blue screen. It’s kind of an exciting time to be able to do those sort of things.

Obviously you need this to be happening to earn your living, but how do you think it affects films? Is it negative or positive?

I think that there’s room for that in some films, and some films are well suited for that. You don’t always want to do that, just because you have a tool, doesn’t mean you should use it. There’s such a thing as, once you’ve got a hammer, everything starts to look like a nail. I think you have to be smart about it. We had the benefit of a healthy budget. Not every movie has the budget we had. We didn’t have an unlimited budget, we certainly had to be frugal about a number of things, but we did have the means to be able to change things, and I think that made Oz a better movie. I’m not sure it would make every movie better, but it certainly worked for Oz.

You say you had to be frugal about things. I take it there were shots that were so expensive they had to be restrained.

Despite the fact that I just talked about how much you can change everything, and how we replaced a bunch of things, at the end of the day, we were able to have 372  non-visual effects shots, and that’s by having the production designers and the art department build partial sets, and be very careful about shooting into them, and not shooting off them. I think by going in with really good intentions about fighting to get  non-visual effects shots, and when you do need to go to visual effects and use that tool, then just embrace it.

Obviously your goal is to hide what you do. Do you find that with something like Oz the Great and the Powerful, the impetus to do so is less, because of the style?

That’s something I thought about a lot while working on the film. Our number one job isn’t to hide things and make them invisible, it’s to serve the story. In some stories it’s really critical to hide that, like any hint of that is going to pull you out of the movie. I think audience expectations for a movie like Oz is that they are going in to this hyper-real environment. They’re not going to Oz to see something they can drive through the country to see, they’re going to see something that hopefully they’ve never seen before, and something that’s beautiful in a way that isn’t in the real world.

You completely replaced Zack Braff’s work on set. Was that the same with Joey King’s performance as the China Girl as well?

We used a marionette to great success when we were filming,  to get a lighting reference, and to get an idea of the performance, and to get improved interaction between live action actors and our CG construct. At the same time, we felt that we needed to video tape and get amazing reference of the actors too. For China Girl, I think the art form was Imageworks animators taking a combination of marionette performance, Joey King’s performance, and their own faith and direction, and building something out of that.

I expect you be not be able to discuss this, but the logical extension of being able to replace someone’s performance with a whole new character, do you ever get called upon to replace elements of an actor’s performance, without us realising?

There definitely have been cases in my history of visual effects where I’ve had to do that.. I’m not sure if there is a sensitivity about it, but I don’t like to talk about it.

Absolutely. How common is that, though?

I’d say it probably varies per director and per film. There’s any number of reasons why you might do that. You might do it instead of doing a reshoot, you might do it to change a line. I think it’s just another tool in the visual effects toolbox. There’s more common visual effects like that in other movies, where there’s aging or de-aging. There’s a lot of digital makeup techniques nowadays. It’s another tool.