Avat3r: Large Animatable Gaussian Reconstruction Model for High-fidelity 3D Head Avatars

TL;DR

Avat3r is a novel model that efficiently creates high-fidelity, animatable 3D head avatars from minimal input images, reducing computational costs and increasing robustness compared to traditional methods.

Contribution

This work introduces Avat3r, the first large reconstruction model that is both animatable and capable of producing high-quality 3D head avatars from few images, utilizing a new prior and simple expression conditioning.

Findings

Competitive performance in few-input and single-input scenarios.

Robust reconstruction from inconsistent or imperfect inputs.

Effective creation of 3D head avatars from diverse image sources.

Abstract

Traditionally, creating photo-realistic 3D head avatars requires a studio-level multi-view capture setup and expensive optimization during test-time, limiting the use of digital human doubles to the VFX industry or offline renderings. To address this shortcoming, we present Avat3r, which regresses a high-quality and animatable 3D head avatar from just a few input images, vastly reducing compute requirements during inference. More specifically, we make Large Reconstruction Models animatable and learn a powerful prior over 3D human heads from a large multi-view video dataset. For better 3D head reconstructions, we employ position maps from DUSt3R and generalized feature maps from the human foundation model Sapiens. To animate the 3D head, our key discovery is that simple cross-attention to an expression code is already sufficient. Finally, we increase robustness by feeding input images with different expressions to our model during training, enabling the reconstruction of 3D head avatars from inconsistent inputs, e.g., an imperfect phone capture with accidental movement, or frames from a monocular video. We compare Avat3r with current state-of-the-art methods for few-input and single-input scenarios, and find that our method has a competitive advantage in both tasks. Finally, we demonstrate the wide applicability of our proposed model, creating 3D head avatars from images of different sources, smartphone captures, single images, and even out-of-domain inputs like antique busts. Project website: https://tobias-kirschstein.github.io/avat3r/