Taylor Swift: Out of the Woods

Few visual effects studios get the opportunity to contribute to music videos as popular as those from Taylor Swift. But Ingenuity Studios, based in Los Angeles and New York, has worked on several, including the pop singer’s ‘Blank Space’, ‘Bad Blood’ and ‘Out of the Woods’ - totaling online views reaching past one billion and each presenting its own set of complex effects challenges.

For ‘Out of the Woods’, in particular, Ingenuity tackled growing vines, avalanches, sand and ice simulations and computer generated wolves, leaning heavily on the capabilities of Houdini to turn 100 shots around in only three weeks.

The CG wolves were one of the first assignments artists at Ingenuity had to consider. They soon realized that the wolves would need photorealistic fur, something that is usually a time consuming task. “We knew,” says Ingenuity Creative Director and VFX Supervisor Grant Miller, “that the wolves would be quite hero but that we wouldn't be able to simulate hair for 20-plus wolves due to time constraints.”

The solution lay in generating the fur in Houdini, as Miller explains: “We created a base groom for the wolves using Houdini's fur system, added custom clumping created with VOPs (VEX operators) on top of that, then transferred the groom to an RGB direction map in the format that V-Ray Fur for Maya expects. This allowed us to render the millions of animated and groomed strands of hair while keeping the scenes extremely light.”

Vines play a central role in ‘Out of the Woods’, with Ingenuity needing to match practical vines filmed on location with CG versions. “The growing vines on the beach and in the forest were filmed clean,” says Miller. “We used seashells as natural tracking markers for the beach scenes and small LED lights in the forest. For shots where Taylor is navigating through vines our Art Director Bruce Everard found a great batch of practical vines to use as a base. We photographed these for reference and then added additional moving vines among the practical ones via deep compositing and a lot of roto.”

But the vines also needed to exhibit their own sense of character, and for that the studio “created long straight vines in SpeedTree to match the reference, then imported the Alembic caches into Houdini,” outlines Miller. “Path deforms in Houdini were used to position and animate the growing vines.”

This gave artists precise control over the curves, timing and noise of the growing vines. “It allowed us to iterate on playblasts and nail down the look and movement very quickly for a given sequence,” states Miller. “There are vines growing in almost every shot for the first minute or so of the video. With Houdini we were able to repurpose vines from previous shots to get up and running quickly while maintaining the manual control we needed to fit the vines in to a given shot and address notes.”

This ice world also exhibits a dramatic avalanche, again realized by Ingenuity in Houdini. “A particle simulation was used to drive the snow flowing down the mountain,” says Miller. “This simulation could be tweaked and previewed in a few minutes making it easy to work on the overall shape and speed of the avalanche. The particles were then converted to a VDB and used as a source for smoke which added the billowing and turbulence you'd expect from a roaring avalanche.”

Along with the main effects for the wolves, vines and ice and sand simulations, Ingenuity also relied on Houdini to craft a swathe of atmospherics such as lightning, falling and blowing leaves and snow, Swift’s shattering dress, fireflies, embers and smoke. These kinds of enhancements were ones the studio was well-versed in, having completed similar work for ‘Bad Blood’ and other projects.

“For ‘Bad Blood’,” notes Miller, “we used Houdini to create smoke, pyro, signal flares, falling embers, and various effects in the bike sequence. The road flares took a fair bit of work to nail down how the smoke behaved. Thankfully we'd done the effect only a month prior for the TV show Brooklyn Nine-Nine. When ‘Bad Blood’ came around all we needed to do was track the flare's position and apply the same setup. That sort of re-use really helps on jobs with tight turnarounds.”

Reflecting on the work in these recent Taylor Swift projects, Miller says he was particularly impressed with the way artists utilized Houdini’s vertex painting tools. “They are a fantastic way to define and visualize a variety of attributes on a given surface. Combined with the powerful stamping features of the Copy SOP you can insert a great amount of artistic input into a complex setup or simulation.”