Rotoscoping, which is modeling 2D animation over existing live-action footage, was once standard use. Walt Disney popularized the use of rotoscoping on many of its classic films, going back to Snow White and Cinderella. But more recent animation uses this technique as well. One of the most obvious examples clocked by fandom was the early-2000s Fox Kids X-Men: Evolution animated series, which rotoscoped over an iconic moment from Buffy the Vampire Slayer’s third season. You can see a side-by-side video in a post from the Preston Ward Condra YouTube account down below:
The scene in question came from X-Men: Evolution’s first season, in the episode “Spyke-cam,” which aired in 2000. It showed Rogue and Kitty Pryde dancing up a storm together. The animators rotoscoped all of their dance moves over images of Sarah Michelle Gellar and Eliza Dushku dancing at the Bronze from the Buffy the Vampire Slayer season three episode “Bad Girls.” As Buffy fans might remember, this is when the Slayer Faith goes rogue (no pun intended) and kills a regular human. This leads to a Buffy vs. Faith showdown, one of the series’ most iconic storylines.
This is but one of many connections between X-Men and Buffy. When Joss Whedon created the character of Buffy, he said that he drew direct inspiration from Kitty Pryde. So it’s only fitting that Kitty on X-Men: Evolution drew inspiration from Buffy in a full circle moment. Although Buffy drew inspiration from Kitty, her surname, Summers, was a nod to the X-Men’s leader Cyclops, a.k.a. Scott Summers. In Whedon’s Astonishing X-Men run, he nearly dropped a joke about Scott having “a cousin who hallucinated fighting vampires.” She was now institutionalised, a reference to the Buffy episode “Normal Again,” where Buffy believed her slayer life was all in her head. However, he decided against it. But the X-Men/Buffy connection has been there since the very start.