TryOnCrafter：透過可渲染的4D試穿代理釋放相機軌跡，實現逼真的影片虛擬試穿

摘要

儘管影片虛擬試穿（VVT）在動態主體上合成逼真服飾疊加方面已取得顯著進展，現有典範仍受制於被動依賴原始相機軌跡，無法滿足全方位視角探索所需的互動自由度。為解決此限制，我們定義了開創性研究前沿：相機可控式影片虛擬試穿（CaM-VVT）。與傳統VVT不同，CaM-VVT不僅需要視點無關的紋理幻覺，還需在任意無約束相機運動下，實現非剛性人體動態與背景環境之間嚴格的結構同步。為應對這些挑戰，我們提出TryOnCrafter——首個專為CaM-VVT任務設計的統一DiT架構框架。有別於隱式像素空間操作，我們引入可渲染4D試穿代理，將人體主體與環境明確解耦。此方法透過將高保真2D試穿先驗蒸餾至基於3DGS的衣著化化身，再經SMPL-X序列驅動並與重建背景點雲進行度量對齊，建立兼具優異紋理密度與運動完整性的穩健結構基礎。我們的代理錨定影片DiT以此穩健結構基礎作為主要幾何錨點，確保合成的逼真影片嚴格受預設軌跡與物理合理形變約束。得益於4D代理的內建可編輯性，TryOnCrafter支援多樣化下游應用，包括人體重新定位、「子彈時間」效果及360度環繞視角觀賞。

English

While Video Virtual Try-on (VVT) has achieved remarkable progress in synthesizing realistic garment overlays on dynamic subjects, existing paradigms remains fundamentally constrained by a passive dependency on source camera trajectories, failing to accommodate the requisite interactive freedom for omnidirectional viewpoint exploration. To address this limitation, we define a pioneering research frontier: Camera-controllable Video Virtual Try-on (CaM-VVT). Unlike conventional VVT, CaM-VVT not only necessitates viewpoint-agnostic texture hallucination but also strict structural synchronization between non-rigid human dynamics and background contexts under arbitrary, unconstrained camera movements. To tackle these challenges, we present TryOnCrafter, the first unified DiT-based framework specifically architected for the CaM-VVT task. Departing from implicit pixel-space manipulation, we introduce a Renderable 4D Try-on Proxy that explicitly decouples the human subject from the environment. This is achieved by distilling high-fidelity 2D try-on priors into a clothed 3DGS-based avatar, which is subsequently animated via SMPL-X sequences and metric-aligned into a reconstructed background point cloud. This proxy establishes a robust structural foundation with superior texture density and motion integrity. Our Proxy-Anchored Video DiT leverages this robust structural foundation as a primary geometric anchor, ensuring that the synthesized photorealistic videos are strictly constrained by prescribed trajectories and physically plausible deformations. Benefiting from the inherent editability of the 4D proxy, TryOnCrafter facilitates diverse downstream applications, including human relocalization, ``bullet time'' effects, and 360-degree orbital viewing.