  This paper targets interactive object-level editing (e.g., deletion,
recoloring, transformation, composition) in dynamic scenes. Recently, some
methods aiming for flexible editing static scenes represented by neural
radiance field (NeRF) have shown impressive synthesis quality, while similar
capabilities in time-variant dynamic scenes remain limited. To solve this
problem, we propose 4D-Editor, an interactive semantic-driven editing
framework, allowing editing multiple objects in a dynamic NeRF with user
strokes on a single frame. We propose an extension to the original dynamic NeRF
by incorporating a hybrid semantic feature distillation to maintain
spatial-temporal consistency after editing. In addition, we design Recursive
Selection Refinement that significantly boosts object segmentation accuracy
within a dynamic NeRF to aid the editing process. Moreover, we develop
Multi-view Reprojection Inpainting to fill holes caused by incomplete scene
capture after editing. Extensive experiments and editing examples on real-world
demonstrate that 4D-Editor achieves photo-realistic editing on dynamic NeRFs.
Project page: https://patrickddj.github.io/4D-Editor
