Novel view synthesis essentially requires AI to 'imagine' unphotographed angles. The difficulty lies in 'large baselines'—showing AI only a frontal view and asking it to generate a profile or even the back of the head. Traditional NeRF and 3DGS methods rely on multi-view reconstruction; when monocular video coverage is insufficient, they produce holes and artifacts. Generative methods can 'paint,' but camera poses are only input as abstract condition vectors, lacking explicit 3D modeling, leading to instability during large rotations.
In the past two years, a third approach has emerged: first use a geometry model to convert the image into a 3D point cloud, then render the target view from the point cloud as a condition for a video diffusion model, as seen in ViewCrafter and NVIDIA's GEN3C. However, the UniWorld-View team discovered two unresolved issues in point cloud rendering: foreground-background tearing and backside light leakage.