Roaring across scorched deserts and rumbling across war-torn city streets comes a trailer for the MMO; World Of Tanks. This two minute trailer took director Steven Ilous across the Atlantic to Imagination Studios, where 60 artists worked for 60 days to create this CG extravaganza. The result – a photorealistic trailer for the game that holds the Guinness World Record for the “Most Players Online Simultaneously on one MMO Server”.
This was my second collaboration with Steven, and a return back to the world of pure CGI, with its own set of challenges. The raw images that Steven brought back with him had a real energy to them, but as great as they looked, Steven was wise enough to know that clean renderered images are simply the beginning of the process, not the end.
Since this was Steven’s first time directing tanks, he needed to rely on certain tricks to convey a sense of scale. Steven; “To prevent consumer confusion, we couldn’t use humans! We tried to offset that by incorporating human artifacts that would subconsciously establish a familiar sense of scale”. You can see this clearly in the shot of a baby doll being crushed by a tank. “I wasn’t quite sure how I would go about applying real world choices to these massive, cumbersome machines. They have a tendency to miniaturize the sets.”
The good news is that colour can help a great deal in this situation. For example, by reducing the contrast and focus on foreground objects, you can kill their volume, and thus reduce the effects of miniaturization. This is one of the tricks we also use in stereoscopic photography and conversion, and it’s amazing how these two simple adjustments can skew the monocular depth cues enough to create a false sense of scale and perspective. We used this technique on the sand dunes in the desert scenes, as well as certain shots in the streets of Berlin.
To recreate the final days of the allies charging through the streets of Berlin, Steven went into incredible detail: he called a photographer friend in Berlin and asked him to take pictures of the cobblestones as a reference for these scenes. He worked very closely with the Wargaming.net team, who were incredibly knowledgeable and helpful. Ultimately this attention to detail paid off in the colour session, because the images we were starting with had subtle details and realistic textures.
For most Berlin shots, I used contrast and density to establish a base grade, which instantly revealed a magenta tint in most shots. Pushing green into the blacks and mid tones helped, but also reduced the intensity of the flames, which I didn’t want. To fix this, I created a secondary correction for the flames, dialing back some of the original warmth. Even with this addition though, the flames felt anaemic.
At this point we started experimenting with blending modes. Just like with Photoshop or any other compositing application, the Quantel Pablo allows you to freely combine the colour tools with paint and compositing, and that includes blending modes. We composited the colour corrected shot over itself and then played with modes like Screen and Overlay. Screen worked particularly well, bringing out the flames nicely. However, I wanted the effect to spare the shadows, so I used a simple luminance key and opacity slider to ‘mix in’ just the right amount of vibrance and contrast.
This is one thing I love about working with a system that allows you to ‘composite with colour’: what would normally take many layers of colour to achieve on a pure colour grading system can simply be achieved using a blending mode and an opacity slider in the Pablo!
Diffusion vs. Sharpening
Many times with CG there is a requirement to use diffusion filters to even out some of the sharpness you get with certain renderers. However, for World Of Tanks we wanted to retain a lot of the sharpness for the tanks themselves. The answer was an unusual approach: we diffused many of the shots using some light grain, before colouring them and finally selectively sharpening them to bring back some of the ‘crispness’. The effect has an almost documentary-like feel to it, and works particularly well with the exteriors.
The bridge above shows this effect. The diffusion combines nicely with all the particle FX, adding to the overcast and dull sky. Where there is contrast though, the ‘unsharp mask’ filter brings out the detail, giving the tanks a real presence and an overall more modern look to piece.
For more examples of Steven’s work, visit his website by following this link.