The final battle in ‘Iron Man 3’ brings together the heroes and villains at night at a floodlit, abandoned marina. This was the primary sequence Marvel approached Cinesite to work on. “We came onto the production just nine weeks before delivery, which is an unusual situation for our team,” said VFX supervisor Simon Stanley-Clamp.

“We had no pre-production background or on-set planning to guide us. The sequence had grown to the extent that the original vendor assigned to it, Weta, still had a number of shots and tasks to complete at that stage. We mainly took care of the sequence opener, as the characters arrive, up to when the shooting starts. All up, between this sequence and some other work, we delivered about one hundred shots, nearly all of which remain in the final cut.”

To get quickly up to speed, Simon chose a team he knew well from other projects and kept their approach straightforward. Avoiding any undue technical experimentation, they stuck with what they knew they were good at, using RenderMan for all renders. If their effects library – which is extensive in terms of explosions, smoke and spark elements – already held a suitable FX pass they would use it instead of starting from scratch. They lacked even the luxury of two or three days in R&D.

Marina Environment

Before: Marina

“The marina environment came to us direct from Weta, who by then had spent several months building up the assets. They handed over the highly detailed models along with their textures, which was a bonus because we could be assured of maintaining scale and looks. We had a LIDAR scan of the marina set to help during layout, plus a couple of live action plates to match to for the topography. Then, about three to four weeks into our work we received some finals from Weta as well, for a clear idea of the overall look and grade. Fortunately, the Iron Man films have a very identifiable look latch into, such as colour scheme.”

After: Marina

With these raw materials, Cinesite’s team went straight into laying out the marina, getting sign-off on the placement

of assets as they went. They had no concepts to work from but used some pre-vis, mainly in the form of early cuts and some bash-composites from editorial. Simon established four views, and they placed their cameras accurately in the scene based on a schematic of the marina. This meant the first pass layouts were based on a true layout. Temporary blocking layouts were produced for each shot and presented to production in the cut and from there, shots could be adjusted to better suit framing for the scene or make a better composition.

Re-purposing and Asset Sharing

For a handful of shots as the gun battle gained momentum, they could re-purpose the live action by nesting it back down into the CG environment, and then on others they did the reverse of that, placing elements back behind the shot plates. In short, the plates were not always intended to exist in the edit as they were captured. They might be reduced, flipped or pulled apart. “These are all standard enough compositing tasks if the team has been on the project from the start. You develop a feeling for composition and how elements should be used. But coming in later on meant some extra layout experimentation,” Simon said.

All communications from production VFX supervisor Chris Townsend came to them via Cinesync conference calls, even the initial brief. There was simply no chance for a face-to-face-meeting. As they got going they were participating in a conference call every day. Simon, amazed at how efficient the production was at handling the work remotely, said, “In total I believe they were working with about 17 or 18 vendors, more than I had artists on my team. Yet the film holds together and never falls into a mosaic of the different teams’ styles.

“Weta’s assets fitted very neatly into our Maya-RenderMan pipeline. Often, asset-sharing needs a lot of back-and-forth communication before the models and textures work properly but Weta’s build and method of hand-over was very efficient,” said Simon.

“At the beginning we had to write a few scripts to convert the file structures and naming, and handle renumbering of textures and assets to something that we could use in our pipeline. However because everything was well packaged up from Weta it became an automatic process by the end, with few manual tweaks. We were also given approved look development turntables, which helped to match our shading and lighting to. Further to that, the shots fortunately didn’t involve rigs or characters to work with, only geometry and architecture.”

Dramatic Lights

The scene is dramatically lit with floodlights that often shine through clouds of smoke and a moist atmosphere. Cinesite put this to their advantage when lighting their work to match this, placing their own smoke elements and atmospheric elements on cards in Nuke and shining digital light through them to give an impression of the path of the follow spots.

Within the marina model came various vehicles such as forklifts, cranes and smaller trucks which the team re-purposed to fill out their own composites, adding and animating headlights and driving them about the scenes. The practical plates were fairly busy with plenty of people and vehicles milling around so they matched their shots to that.

The distant environment and lights came from their matte painting department who produced a massive, oversized digital matte painting based on a practical marina. It was used very subtly, placed into the far distance and shown well out of focus.

Stark Industries

Stark Industries

Apart from this big marina sequence the team also completed a wide overhead establishing shot of the Stark Industries complex. A helicopter plate had been captured of a university campus, which Chris Townsend wanted to look more like an industrial science park. They vegetated the surrounding area, removed some of the roads and then built up the park with foliage and trees.

The environment department re-purposed some buildings in the plate by either re-positioning them or placing them on cards to accommodate a camera move. The helipad was built on top of the existing architecture. The grass was matte painted down and the trees were created with Speed Tree software to match the existing foliage, ‘growing’ additional trees to drop in.

They have started using Speed Tree quite regularly now, including on their recent film project ‘WWZ’. It is an application used to create 3D animated plants and trees for animation and VFX shots and integrates with other digital content packages like Maya.

Further shots the team completed included several green screen composites for the in-car shots, all at night using extra reflections on the windows and grading with interactive lights flashing across the faces. Also, the villain Savin’s head, seen closely shaved in the movie, had to be reconstructed following a re-shoot that was completed after the actor had grown his hair back. They had a CyberScan and texture passes of the character, but did not need to resort to 3D methodology for the clean up, achieving the rebuild completely in 2D.