Retrieval-Augmented Gaussian Avatars: Improving Expression Generalization

Fuente: arXiv
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Autori principali: Levy, Matan, Habib, Gavriel, Tzachor, Issar, Samuel, Dvir, Ben-Ari, Rami, Darshan, Nir, Litany, Or, Lischinski, Dani
Natura: Preprint
Pubblicazione: 2026
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author Levy, Matan
Habib, Gavriel
Tzachor, Issar
Samuel, Dvir
Ben-Ari, Rami
Darshan, Nir
Litany, Or
Lischinski, Dani
author_facet Levy, Matan
Habib, Gavriel
Tzachor, Issar
Samuel, Dvir
Ben-Ari, Rami
Darshan, Nir
Litany, Or
Lischinski, Dani
contents Template-free animatable head avatars can achieve high visual fidelity by learning expression-dependent facial deformation directly from a subject's capture, avoiding parametric face templates and hand-designed blendshape spaces. However, since learned deformation is supervised only by the expressions observed for a single identity, these models suffer from limited expression coverage and often struggle when driven by motions that deviate from the training distribution. We introduce RAF (Retrieval-Augmented Faces), a simple training-time augmentation designed for template-free head avatars that learn deformation from data. RAF constructs a large unlabeled expression bank and, during training, replaces a subset of the subject's expression features with nearest-neighbor expressions retrieved from this bank while still reconstructing the subject's original frames. This exposes the deformation field to a broader range of expression conditions, encouraging stronger identity-expression decoupling and improving robustness to expression distribution shift without requiring paired cross-identity data, additional annotations, or architectural changes. We further analyze how retrieval augmentation increases expression diversity and validate retrieval quality with a user study showing that retrieved neighbors are perceptually closer in expression and pose. Experiments on the NeRSemble benchmark demonstrate that RAF consistently improves expression fidelity over the baseline, in both self-driving and cross-driving scenarios.
format Preprint
id arxiv_https___arxiv_org_abs_2603_08645
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Retrieval-Augmented Gaussian Avatars: Improving Expression Generalization
Levy, Matan
Habib, Gavriel
Tzachor, Issar
Samuel, Dvir
Ben-Ari, Rami
Darshan, Nir
Litany, Or
Lischinski, Dani
Computer Vision and Pattern Recognition
Graphics
Machine Learning
Template-free animatable head avatars can achieve high visual fidelity by learning expression-dependent facial deformation directly from a subject's capture, avoiding parametric face templates and hand-designed blendshape spaces. However, since learned deformation is supervised only by the expressions observed for a single identity, these models suffer from limited expression coverage and often struggle when driven by motions that deviate from the training distribution. We introduce RAF (Retrieval-Augmented Faces), a simple training-time augmentation designed for template-free head avatars that learn deformation from data. RAF constructs a large unlabeled expression bank and, during training, replaces a subset of the subject's expression features with nearest-neighbor expressions retrieved from this bank while still reconstructing the subject's original frames. This exposes the deformation field to a broader range of expression conditions, encouraging stronger identity-expression decoupling and improving robustness to expression distribution shift without requiring paired cross-identity data, additional annotations, or architectural changes. We further analyze how retrieval augmentation increases expression diversity and validate retrieval quality with a user study showing that retrieved neighbors are perceptually closer in expression and pose. Experiments on the NeRSemble benchmark demonstrate that RAF consistently improves expression fidelity over the baseline, in both self-driving and cross-driving scenarios.
title Retrieval-Augmented Gaussian Avatars: Improving Expression Generalization
topic Computer Vision and Pattern Recognition
Graphics
Machine Learning
url https://arxiv.org/abs/2603.08645