Last night in the US a segment of The Simpsons was broadcast live. Homer Simpson spoke live to the audience in a groundbreaking television first.

Voice actor Dan Castellaneta improvised a three-minute live section of the cartoon, talking about current events and answering viewer's phone-in questions. And all without a drop in the usual animation quality.

This was possible because The Simpsons team used Adobe Character Animator - a new feature in After Effects CC that lip syncs the actor and animates the on-screen mouth to reflect the live words.

Keyboard commands can also be used to instantly animate aspects of a 2D cartoon.

Layered characters can be drawn and created in Photoshop or Illustrator and imported into Character Animator. Then a webcam can be set to capture the live movements of the actor and translate those in animation.

This is the process used by The Simpsons for the live episode.

The software was originally devised for off-screen aid, as a tool for animators to see how a performance might work in real time. However, the potential for broadcast was soon realised.

"We created a live interface so animators could get immediate feedback on their performances, but as more people asked about live broadcasts, we knew we had something special," said David Simons, co-creator of Adobe After Effects.

"I’ve been a fan of The Simpsons since the early 90s, so, when they contacted us, we jumped at the opportunity to work with them on their first live broadcast."