Given the Picasso-esque posing of Charles Schulz’s beloved characters, Blue Sky departed from its customary procedures for the Oscar-contending The Peanuts Movie. This included rigging and materials. They created hundreds of poses, but to hit all of the poses that Schulz drew and stay on model, they built a system of parts that they could move, slide, switch out and replace. When I was up at Blue Sky last summer, I spoke with Sabine Heller, character development supervisor, Justin Leach, rigging supervisor and Nikki Tomaino, lead materials tech director.
Bill Desowitz: Tell us about the process of creating a very specific style to adapt Schulz’s hand-drawn expressions.
Sabine Heller: We spent 18 months on just one character, Charlie Brown. We basically made a deal with the production manager to say this was so difficult that we have to figure it out on one character first and then we can move on to the other characters.
BD: So I understand that you had to add all of these custom controls to switch poses.
SH: Yeah, it’s really interesting because we had to find one model that we could rig and it was hard because normally it doesn’t move all the way around. But they trusted us to make one character and then all the other characters from that character. We made a body that fits all the kids and a head that adjusts to make it also fit the other kids. You could even put a dress from Lucy on Charlie and the hair so it looks exactly like Lucy. You to bring it into this character view so it actually looks like her, and then, of course, when you put at the end the pose of animation, it looks more like him. In all, we had six character views. When you look at it, you can see that the nose moves down, and the ears move up and then the shape of the head completely changes. So we were able to get a control and ask for a specific character view and that character view in this instance is the profile and make it look more like Charlie Brown.
BD: What was it like studying the artwork?
SH: It was a very specific language and we had to pay attention to the direction of the lines when when he looks left or he looks right. And when he looks the periwinkles.
BD: And his hair is very strange.
SH: Design called it popcorn.There were a lot of food references. M&Ms and yogurt for how they integrate to skin. And in animation they compared them to melted chocolate chips.And we made it so we could slide it all over the face and they would always be on the surface but totally disposable, which was something we don’t normally do. And we had expression lines and made special set-ups because Charlie Brown blinks differently because he has no eye lids. So we made a half-way eye cut with the eye lid for the blinks.
SH: We had a special plug-in for that. You can visualize it in Maya, because otherwise that wouldn’t be possible.
BD: And what about Snoopy?
Justin Leach: He’s really interesting because he has two eyes on the side of his head. We had a default pose when you rigged him and then when you turn on our flip attribute you can see he has two eyes on one side of the face. Another interesting thing is that all of the characters have to have huge expressions. It gets so crazy that what we ended up doing is create a special plug-in in R&D to make something that only moves on the surface. Normally, in Maya, what we do is move it up and get a cheek bulge. That’s something that we didn’t do at all with these characters. We kept the look-line on the surface off the face and always follow along the silhouette.
BD: That’s tough for the computer.
JL: Yes, going around curved surfaces doesn’t work so well normally, but that was one of the key things we created in R&D. And this was difficult for a lot of other departments because moving this topology all the way around, so something before that was [on the bottom] is suddenly way up [on top], which, of course, for fur and materials is not the easiest thing to handle.
BD: What about handling Schulz’s particular use of motion blur?
SH: That’s another interesting thing. When Charles Schulz drew the characters in really fast motion, he attempted motion blur by showing multiple limbs. He does it with hands, the whole arm, or heads, feet and heads even. And we embraced that and wanted to bring it within the 3D world. And we decided to approach it very similar with multiples. And, of course, we animated this on 2s, so it works really well with the head turns and you get that nice snappiness. But it also allows you to get away with some things. There is no in-between where you see that it’s blurry. But your eye sees it as motion blur because it’s so fast.
JL: It’s also fun too because we also added the accent with TVPaint. That’s actually 2D painted on later.
SH: And to make that multiple lens we really had to decide how we were going to do it because the normal approach would be to create different assets for [body parts]. But we had a meeting and realized to do it would be an extra 14 pieces per character, per outfit, and I actually calculated that in the end it would be 2,940 extra pieces we would have to create for that. What we decided to do was a very different approach that we called ghostlands and within Snoopy you had switches. You’d say, “I want a left leg,” and there it is, and you’d bring in another Snoopy and say, “I want the arm,” for example. Basically, what it does is turn everything else off. The eye rig is actually so heavy because there is so much that you can do with it…it’s all turned off. So that’s all basically you later on have to carry in the scene, which is really nice. JL: And also it’s the same rig so you can transfer the animation from your hero character to the copies and then you just have to slightly offset it.
SH: This was win-win because we didn’t have to support the whole pipeline. We developed also something that would close this automatically on render time so it would render as a full object and fill the surface.
BD: And how did this work with materials?
Nikki Tomaino: We needed to develop this technology for this strange way of working. For me, that was the theme: we had to work in a way that we never had before. In materials, in particular, when we get the character from modeling, we get it in that T pose. Normally, we apply our materials but you’d get a blush that gave you a really hard line. So, in the end what we had to do was utilize a lot of the pieces and parts of the rig to produce materials. For example, the sliding eyeballs. If we were to take this eyeball geometry and use that as non-renderable geometry, that creates a black and white control signal and we could use that to affect color, bump, roughness, transmittance. We used materials to create eye sockets (M&Ms and yogurt), we had these periwinkles to create that really subtle bump effect. You don’t necessarily see it but something would feel missing if it weren’t there. We essentially learned had to rig in the materials department.
And while we were developing the look of the skin on the characters, because they were all sharing the same rig, we were able to build a library of materials that they would share. Like rigging, we had to make the same deal with production. It gave us a lot of freedom, actually, to really develop the look. One of the biggest challenges was being subtle. How do we translate Sparky’s very beautiful 2D comic strip into 3D and not go hyper-realistic? So we used the squint test. So if we were going to create a garment on a character, leather, tree bark and all that stuff, and when you squinted, if you could still see all that texture, then it was too much. You needed to go back in and pull some out.
The other thing that was really important was to embrace the ink lines. So like they did in the rig, which gave the animators all of that control to make the lip lines really wiggly and the periwinkles really wiggly, they did that in modeling as well. There were no straights, there were no perfect circles. We did the same thing in materials. There are no straight lines. When we did our stitching, there was always a little wiggle in it. What this meant for us was we spent 18 months developing the characters’ skin textures, the garments, and normally it’s easy for us to flow into the set pipeline. But when we did that it looked so out of place because the sets are so detailed. It wasn’t until we got it all the way through materials and even all the way into shot lighting, we needed to go back in and revisit. We had to dive into unconventional photo reference. One day I was literally eating grapes and was developing Charlie Brown’s skin and not knowing where to go and realized — that’s it! And we used what some might call primitive approaches to doing materials. We did it procedurally because it was the only way to get the expression lines. It was such a fun experience, trying to find these things.