Character Animation and Lip Syncing in Three.js using Theater.js

Introduction: Animating 3D characters with Theater.js provides a flexible way to create realistic motion. When combined with speech synthesis, it can also be used for lip-syncing animations.

Implementation: By animating a character’s mouth position based on speech audio, we can create a talking avatar:

theater.addActor("character", { mouthOpen: 0 });
function speak(text) {
    const utterance = new SpeechSynthesisUtterance(text);
    speechSynthesis.speak(utterance);
    utterance.onstart = () => {
        theater.getActor("character").play({ mouthOpen: 1 });
    };
    utterance.onend = () => {
        theater.getActor("character").play({ mouthOpen: 0 });
    };
}

Conclusion: This method allows for lifelike animations and interactions in Three.js, making it ideal for virtual assistants or storytelling applications.