đ¤ AI Summary
This work addresses the âmulti-face Janusâ problem in text-to-3D generationâcharacterized by cross-view geometric inconsistency and duplicated structuresâarising from score distillationâs inherent bias toward canonical poses. We propose Uniform Score Distillation (USD), a novel framework that explicitly models and corrects the marginal pose distribution to enforce uniformity, thereby eliminating canonical-pose bias. Our key innovations include: (i) a training-free pose classifier coupled with an auxiliary function to estimate and regularize pose marginals; and (ii) noise-state approximation and marginal constraint modeling to reshape pose distributions without additional training. Experiments demonstrate that USD significantly mitigates the multi-face Janus phenomenon, achieving state-of-the-art performance in multi-view consistency, geometric completeness, and textâ3D alignmentâoutperforming existing methods across all three metrics.
đ Abstract
Current text-to-3D generation methods based on score distillation often suffer from geometric inconsistencies, leading to repeated patterns across different poses of 3D assets. This issue, known as the Multi-Face Janus problem, arises because existing methods struggle to maintain consistency across varying poses and are biased toward a canonical pose. While recent work has improved pose control and approximation, these efforts are still limited by this inherent bias, which skews the guidance during generation. To address this, we propose a solution called RecDreamer, which reshapes the underlying data distribution to achieve a more consistent pose representation. The core idea behind our method is to rectify the prior distribution, ensuring that pose variation is uniformly distributed rather than biased toward a canonical form. By modifying the prescribed distribution through an auxiliary function, we can reconstruct the density of the distribution to ensure compliance with specific marginal constraints. In particular, we ensure that the marginal distribution of poses follows a uniform distribution, thereby eliminating the biases introduced by the prior knowledge. We incorporate this rectified data distribution into existing score distillation algorithms, a process we refer to as uniform score distillation. To efficiently compute the posterior distribution required for the auxiliary function, RecDreamer introduces a training-free classifier that estimates pose categories in a plug-and-play manner. Additionally, we utilize various approximation techniques for noisy states, significantly improving system performance. Our experimental results demonstrate that RecDreamer effectively mitigates the Multi-Face Janus problem, leading to more consistent 3D asset generation across different poses.