Outside of the technical aspects, there are some little things that are also important. Steve Rosenbaum taught me that if a supervisor’s talking, you should be writing. It instills confidence that all the comments I say will get done. A lot of times people don’t write, so I won’t even throw all of my ideas out because I know they’ll fall through the cracks. They’ll just address the big ones. Just because I talk about one thing for 10 minutes and say another thing quickly, it doesn’t mean they’re not equally important. That little thing I just threw out there will stop it from finalling just like the thing I went on about for 10 minutes. If a supervisor’s talking, write it. You won’t remember. You’ll say, “Oh yeah, yeah that’s obvious,” and later you won’t remember. It’s easier to have it all listed and you just go through and check it off. The supervisor’s going to remember and a list makes things so much easier. Another thing is to try not to make excuses. I hate it when you come by and an artist says this didn’t work, and this, and that, and this, or that, and it’s this big long story. Then I ask what they have to show, and they say nothing. I understand the process. If I ask if you did it and you say you’ll have it later, I’ll say OK. I’ll respect you. You don’t need to make excuses.

DP: What do you think the role of image-based lighting and global illumination will be in the near future?

[Figure 3] A scene presenting live-action lighting difficulties in the 1999 film Stuart Little.

JB: I studied the hell out of that. I was looking at some of the high dynamic range things. It works for certain instances, but it’s not flexible in terms of moving a light. Say you have an environment and you use it to automatically create the lighting, and then you want to stick a little creature in it, like a Stuart Little (see Figure 3). Well, when they lit the set, they didn’t light the mouse because the mouse wasn’t there. So the set’s lit well, but it’s like when we did the Centaur on Harry Potter. OK, the set’s lit, but there’s no Centaur, and we didn’t even light the set as if the Centaur was there. If there was a real creature there, the DP would add specials that don’t affect the surrounding, but that light him. That’s totally omitted in this scenario. So now when we come back to the digital effects house and we’re starting to put our creatures into the scene, the VFX supe kind of plays that role. He plays the role of DP. We talked to a guy who’s doing a lot of research with HDR (High Dynamic Range) and a ball and eight pictures. He’s doing some great research and we talked to him for a while because he had done some really beautiful pictures. We asked, “What if I want to put a creature in and use that?” He said you can do that. So then we asked, “What if I want to give it a little rim?” That’s when it got really difficult. That doesn’t mean it’s dead or it doesn’t work. I’m just saying there are many more considerations. Even if I duplicate the exact values of the scene, that’s not the lighting I want for my subject. It’s a great starting place, as long as you can go from there and add your specials and flag lights off. You just need to think it out. We wanted to do something like that on Potter, but what had been implemented in the past was what we would have gotten. You set up the ball (chrome reference sphere) in an environment, shoot your pictures, and then take those energy readings. That’s your lighting, period. We also needed to be able to sit there and add and manipulate lights.

I love the silver balls and the information they provide. I wrote code on Anaconda that took the image of the ball, cropped it in as a little texture, focused in on the highlights, and gave you a vector of where the light came from. It didn’t give you position, but it gave you the direction it came from. We used distant lights in Renderman, with parallel rays, and the lighting in Anaconda took about 10 minutes. Those were our lights, period. We never moved them. We did balance the intensities, since the evaluations did not include intensity or color. We could have included those as well, but didn’t have time to automate it. It gave you the automatic lights and then I just sat there and balanced it. Most of the lighting was in the shader. We kind of got caught up on things with Potter, but I had recorded images on set with two silver balls in each scene. One ball gives you a vector, but with two balls and two vectors, their intersection gives you light position. It’s easy. I can code that now, but we just never did. On the set of Potter, I shot two balls, but we just never got the chance to code it up. Otherwise, we could have gotten the positions. That actually integrates into the existing pipeline we have now.