HOW WERE THE FLAMING DOTHRAKI SWORDS CREATED FOR GAME OF THRONES EPISODE, THE LONG NIGHT?
The impressive battle in The
Long Night is hauntingly revealed in fiery attacks that crash through the darkness. The first charge of the Dothraki begins with a vast army wielding swords that are ignited in a wave of fire by the will of Melisandre. Our job was to set every Dothraki sword on fire to persuasively signify the battle had begun.
We initially approached the task through our standard pipeline, building a library of fire swords in FX and tracking them as 2D cards. But when we received the turnover, we realised how timeconsuming this would be, especially for comp. There were hundreds of Dothraki and each fire element would need to be hand-tracked, as well as the timing offset to match the motion and choreography in the plate. A few real flaming swords were shot on the live set, and for safety reasons they could only use them on the first row. The rest were LED props designed to cast interactive light on the characters.
We took advantage of the light cast by the LEDS and built a system in Nuke plugin Eddy that could drive multiple fire simulations over the Luma Key in the plate. This gave us two advantages: there was no need to hand-track each sword, nor to search a library and offset the timing of each element.
Our first step was to build a template in Eddy that replicated the characteristics of the LED swords shot on set. Because the Eddy combustion template uses physically correct parameters, we were able to research the correct physics of the flames, such as combustion temperature, cooling rates and fuel expansion, and input the correct data from the start. Beginning with physically correct data brought us to a resolved solution much faster than if we had hypothesized the parameters.
Once the look of the effect satisfactorily matched the live-action fire, we extended the template to drive the fuel injection with the Luma Key of the LED lights. The resulting advancement from our initial tests was astonishing.
Creating the flames as a single simulation enabled us to ensure that each was unique. Every sword had its timing and causality, and interacted with the same wind flows. In addition, each of them reacted to the motion of the actor and was perfectly tracked.
Our final task was to art direct and choreograph each flame, which turned out to be relatively simple. All we had to do was control the Luma Key with roto. If the client wanted to turn a particular sword on or off at a specific time, we could paint it off or roto it in, then launch the Nuke script on our render farm to get the full simulation comped and ready to be presented in less than an hour.
Eddy proved to be an incredible tool for this effect. Because it is GPU based, simulation and rendering are incredibly fast. We were able to simulate and render between one and five minutes per frame, which gave us the ability to do multiple iterations of a shot per day and hit our targets with unprecedented speed and accuracy.