UVRelief: A Surface Codec for Avatar-as-Image Generation

Generating human avatars as an Avatar-as-Image representation has become an active and rapidly growing research direction, where we map an avatar onto a shared UV domain over a parametric body model and turn 3D generation into a 2D problem. Realizing this potential, however, hinges on how to obtain a compact latent space for Avatar-as-Image generation. We present UVRelief, a surface codec for Avatar-as-Image generation that encodes a human as a UV-native relative shape: given a textured mesh and its fitted SMPL-X model, UVRelief bakes surface geometry and appearance into Relief Maps, where each texel stores a relief displacement relative to the SMPL-X surface and a texture signal. Built on these maps, a VAE encodes them into a compact UV-structured latent space and decodes texel-aligned 3D Gaussian attributes under rendering supervision, and a flow-matching prior is trained in this latent space for image-conditioned 3D avatar generation. Extensive experiments show that UVRelief improves reconstruction fidelity and achieves competitive generation quality compared with existing multi-view and latent avatar generation methods.