Atomic Arts also replaced the paper boat in the plates with a computer animated boat. “The boat had to travel in a very specific trajectory,” said Ken Wallace, “and so, that ended up being a CG boat.” The sequence starts with a closeup of Georgie placing the boat into the water running alongside the gutter. “In the plate,” said Clwyd Edwards, “the young actor was actually holding a practical boat, which he placed into the water. But Andy wanted very specific animation on the boat, and so we ended up taking out the practical boat and replacing it with a CG one, even in that first shot. That was a little challenging, just because of how close it was, and the way the boat had to interact with the water. Then, the boat was CG throughout its travel through the gutter, because they just couldn’t get the performance they wanted with the practical boat. The very last shot, where the boat drops into the storm drain, was practical – but that was it.” One of the considerations in animating the CG boat was ensuring that its speed in relation to Georgie, chasing after it, remained consistent. “Andy wanted the boat to always be getting away from Georgie,” noted Edwards, “and it took a few iterations to get that just right. Once we had the animation correct, we rendered and lit the boat, using HDRIs from the set. And then, to make it look as if the boat was actually sitting in the water, especially in closeups, we created a small patch of CG water and tracked it, matching the water in the plates the best we could. We used that patch as a holdout for the boat, and then we added some white foam particles around it. That seemed to work quite well.” Even in wider shots, the practical water in the gutters had to be helped along. An in-house visual effects team overseen by Ken Wallace and Nick Brooks shot water elements, which Atomic Arts integrated into the plates to create a better, more art-directed water flow.