Red Tails: Pixomondo wrecks planes and trains

For Anthony Hemingway’s Red Tails, Pixomondo drew on its worldwide resources to collaborate with Industrial Light & Magic on the film’s aerial shots and battle visual effects, which tell the story of the ‘Tuskegee’ African American pilots during WWII. Pixomondo VFX supervisor Bjørn Mayer, who shared duties with Boris Schmidt, breaks down the train attack and other key sequences from the George Lucas-produced film.

Also, watch fxguidetv #132 with Red Tails animation supervisor Paul Kavanagh from ILM.

fxg: What were the main shots Pixomondo worked on for Red Tails?

Mayer: We started at the end of August in 2010 working together with ILM. We had two reels to work on, almost 40 minutes of the movie. We had multiple sequences, including the train crash, a truck attack, some scenes where they fly with the bombers to Berlin, an airplane crash, an attack on a German destroyer ship and a reconstruction of a 1940s Pentagon. The end result was about 540 shots out of more than 1,500 shots in the whole movie.

Watch the train sequence.

fxg: Let’s talk about the train crash – how did you approach that sequence?

Mayer: When we joined the project, the train crash was already pretty far progressed in terms of previs, which had been done at Skywalker Ranch. Initially the shots were wider, but as we started to work on it we suggested there could be some more close-ups, seeing the train’s engine somersault. We suggested that to Craig Hammack (the overall visual effects supervisor), Paul Kavanagh (animation director) and George Lucas and they liked it and went for it. So we started to previs that out and took it through to animation and all of the debris flying around.

fxg: How did they shoot elements to make up the crash?

Mayer: The train was filmed somewhere in the Czech Republic. It was just a train on a field driving from one end of the field to the other, doing this over and over again. We put a mountain on one end of the field – this was the safe exit of the train if it made it to the tunnel to escape the American airplanes. In the wider shots the train was CG, mostly with real Germans scurrying around but sometimes they are digi-doubles.

When the character Lighting is shooting the train from over the hill, that was a full CG train and plane. The cockpit was a greenscreen mock-up with the pilot. Then when the train explodes and does a somersault it was fully CG. We had a lot of simulated elements for smoke and fire, but we also spiced it up with other elements they shot for the movie, either from witness cams or other footage.

fxg: What was Pixomondo’s approach to the hard surface models of the planes and the train in that scene?

Mayer: The planes we shared with ILM – we received most of the assets from them. We adapted them a little to our needs, so sometimes for very close-up shots we needed to add to them. We had textures for the hero American and German planes and we then rigged the planes for our software packages.

The train we built from scratch. We built the engine and wagons, and we made several destruction stages that we blended over, and there was a lot of simulation that let the train break and fly away. We had simulated objects around a hand-animated core, basically. We used 3ds Max for the animation, with Fume and Thinking Particles for the fire and smoke.

fxg: Can you talk about how you built up the animation for the final crash?

Mayer: The animation supe and I tied some T-boxes together with tape and drove the train around on a table. We went through all the stages of where the cars should fly and what they should do and how they should break off. Then we did some very rough animation in Max with boxes and cubes. From there it got more and more refined, doing it with some low-res train models, and then presented it to Paul Kavanagh and Craig Hammack.

fxg: Another big part of that sequence was the tracer fire – how was that accomplished?

Mayer: We developed the tracers for the truck attack earlier in the film. Craig was very specific about the look of those, and he gave us some reference of shots ILM had done before. We had some real-world footage from WWII too. The tracer itself is just a long motion blur, baking in all the camera shake and the vibration of the engine. It looks a little bit like lightning – and they are not perfectly straight either.

fxg: What was your compositing tool for the train sequence?

Mayer: We used Nuke mostly. The train crash sequence was divided between the Stuttgart and Berlin facilities. Berlin was doing most of the simulation work and rendering – and compositing was divided between Berlin and Stuttgart.

fxg: You also worked on the attack of the German destroyer. What were the challenges of that set of shots?

Mayer: George was not too specific about what kind of ship it should be, so we had a concept of a WWII-looking ship with a swastika on it. We built the model in Stuttgart and we textured it in LA and added the explosion and the breaking. For the water we just had a plane in Max with a bump map – the trick was to reflect the sky in the water, so we made a sky environment for that.

fxg: You also mentioned the earlier truck attack – can you talk about that?

Mayer: You see the truck from an aerial perspective, and then when it gets shot you see it from the front coming down the road, and it explodes. When it was shot, the truck was filmed just running down the side of the street and then it stops and smokes a little bit. We had to create a huge explosion instead, so we made a truck with a tarp on top in CG that burned and had parts breaking away with barrels flying away from it.

For the CG fire for the truck and other shots, we used FumeFX and Thinking Particles – we would emit fuel and then from heat it would ignite and then it gets swirled by force fields to make it look realistic. The smoke that was emitted was very thick and swirly – we matched it from the plate but also simulated additional layers on top.

fxg: And finally, what was involved in re-creating the Pentagon?

Mayer: We had to create it to match the 1944-era Pentagon. Everything around it – the streets, the parking lots, trees – was all CG. George gave us some reference and we researched pictures and floor plans – I’m pretty sure that some of us got onto the watch list for that!

All images and clips copyright © 2012 Lucasfilm Ltd. Care of Pixomondo.