dock10's VFX specialists have provided a big world VFX build of a devastated city seen from a moving helicopter as it flies across a dramatically changing landscape. "The client came to us with some pre-shot footage that needed the background changed," says Alex Dubus, VFX Supervisor at dock10. "It needed to depict a transition between two types of environment, and we knew right from the beginning that this would be a big world build, since the camera would have to see approximately 12 blocks of destroyed city."
"We started by analysing cityscapes and rooftops," explains Hayley Leonard, Senior CG Artist at dock10. "In the image references, we found they all had a substantial amount of wear and tear. I wanted to make sure that the rooves retained this level of detail, and for this we thought it was best to use an actual photograph and then build the model from that. We also needed to undistort the plate, so that the straight lines matched up to the lines and edges of the CG objects."
"To help bed in the comp," continues Alex, "we rendered in various passes of CG fog to make sure that the light was properly occluded and that the right shadows were cast. We then rendered the various passes needed for comp to assemble it all. All the compositing was done in Nuke with the usual process of Rotoing and assembling all the layers. Then, extra detail was added like some fires and hero smokes using cards and mattes."
The client then decided to take the shot even further, as Alex explains: "Once the main city shot was completed, the client came back to us with a new request. He wanted to add a third scene to the transition. In many ways, this was fairly easy for us because we had already prepped the shot and there was a lit scene already. He wanted an ocean to be the third scene so we just went ahead and created that in CG and rendered it out."
The final shot involves transitions between countryside, ocean and urban environments, with a spectacular flyover taking in more than 12 blocks of devastated city. The urban build was by far the most complex and challenging, requiring meticulous research and attention to detail to ensure that it looks and feels as realistic as possible.