How Blinkink had to solve some interesting previs, stop-motion and 3D printing challenges for the promo.
‘Extreme by Nature’, a spot for the BBC Winter Olympics coverage, begins with a view of an ice cube. Inside, representations of winter olympians start moving inside, before breaking free to now be seen participating in sports like downhill racing and skeleton sledding inside snow-like ‘boxed’ vignettes.
It’s a stunning spot, made even more spectacular by the fact that the characters animated inside the ice cubes and snow-box vignettes were achieved with a large proportion of in-camera methods, including 3D printed materials (147 pieces in total), stop-motion and motion control. All of this was overseen by Blinkink and director Balázs Simon, for BBC Creative.
In this excerpt from issue #6 of befores & afters magazine, Simon outlines the process of making ‘Extreme by Nature’ for befores & afters, including the challenges of finding the right way to visualize the imagery and realize it with in-camera techniques.
b&a: In the ‘snow’ 3D prints, you see them going downhill or on the skeleton bobsleds. But it’s almost like a cut-down version of those backgrounds, which I really liked. How did you work out how much to show?
Balázs Simon: Yes, another difficulty to pull off was to actually include the environment in the prints. We had to make the characters feel that they are somewhere, and, remember, environments can be really deep compared to your subject. Your subject is just a very thin slice in that space. There’s just so much stuff happening around that character. Then when you start rotating with the camera, that space can extend to a lot of directions.
The challenge was, you either have to print a huge space, or you have to somehow compress all that space into the print, and that is what’s happening here. It’s getting smaller and smaller. It’s distorted, these trees are much bigger than the trees at the back, and they are not even close to being a real size compared to the character. It’s a simple, forced perspective trick, which was done in Houdini and it’s an algorithm that starts distorting the whole space into the cube based on our camera viewing position in an artist-controllable way.
We could select these ranges where we want distortion to happen. We could actually select the space that our character is in–so that’s not distorted–but then the space is crushed or compressed into the cube.
That was quite a challenge to figure out, because when you are 3D printing it, you need to have a thickness for the print itself. When you have, say, a tree trunk, for example, it will just shrink down to a couple of centimeters in real life. In print, it’ll be paper-thin, and you just can’t print it. It won’t hold its weight. So we also had to figure out, okay, we have to do measurements of thickness and we have to make it more thick, but it should also start to get thick towards the camera so you can’t really see that it’s cheated.
Also, we had to make sure that the underside has thickness, and that is something you can actually figure out after you’ve done the compression. Otherwise, it’ll just have an unreliable, varying thickness based on the camera position, and that can also mess up the print.
b&a: That’s fascinating. Did you realize this before any 3D printing? Or was there a testing process where you went, Oh, of course, I want to just print these boxes, but the tree is a hundred meters away that I want to include, so I therefore have to deal with the perspective issue?
Balázs Simon: We realized it during the previs. So, when the scenes were done, we thought, it looks good, let’s cut them out. And it just fell apart, horribly, without this distortion. As a viewer, you didn’t understand what the character was doing because the environment under it was also just changing so fast. And you didn’t understand how the character moved because you didn’t have that point of reference. That’s when we realized, okay, it’s not working, we have to do something. In the end, it turned into one of the most interesting aspects of the whole film, I think.
b&a: Yes, because watching it, I was like, Wow, what is this? Is it CG? Is it a print? Is it something else?
Balázs Simon: Another interesting part of all this is that we had a moving 3D camera and we had a moving real-life camera as well. So, when you move just the 3D camera and produce the prints based on that, the movement is ‘printed’ into the cube. It’s like when you do a running loop of a character and the environment just whizzes by, but the character stays at the same place–it’s still like a camera is following that character.
Here, some camera movement is printed, but some is actually photographed. We have a camera moving around the skeleton sled racer, for example, and pushing in on the character. So, how do we previs that? To get the right feel, we just animated one camera around space.
But how do you separate that movement into what should be printed and what should be programmed on the motion control system? That was an interesting challenge, creating these two half-movements, when you put the two together.
Read the full article in issue #6.Need After Effects and other VFX plugins? Find them at Toolfarm.