Controllable Expressivity for Three-Dimensional Talking Avatars

Abstract

This internal reference article examines controllable expressivity in three-dimensional talking avatars through a design-and-assurance lens. It synthesizes the allocated target literature without reporting new experiments, observations, or performance estimates. The analysis treats the practical unit of review as a speech signal, facial and ocular controls, rendering pipeline, audience judgment, and release gate. That framing keeps technical mechanisms, evidence quality, user consequences, and institutional controls visible in the same argument. Particular attention is given to how modular control can support expression, evaluation, and safety. The review distinguishes what each cited source directly addresses from the cross-domain principles used for internal comparison. It argues that credible adoption depends on traceable requirements, context-sensitive evaluation, explicit uncertainty, and a documented path for human intervention. The result is a structured reference for teams considering telepresence, digital instruction, and accessible interfaces, especially where uncanny behavior, identity misuse, and aesthetic bias could turn a technically plausible component into an unreliable system. The article is intended to support scoping, design review, and evidence planning; it is not a claim of product readiness or an original empirical study.