Factorized Motion Fields for Fast Sparse Input Dynamic View Synthesis
This addresses the challenge of fast dynamic view synthesis with limited camera views, which is incremental as it builds on existing explicit representations by adding motion modeling.
The paper tackles the problem of learning dynamic radiance fields from sparse input viewpoints, which is under-constrained, by designing an explicit factorized motion model and using flow priors for regularization, achieving very good performance on multi-view datasets.
Designing a 3D representation of a dynamic scene for fast optimization and rendering is a challenging task. While recent explicit representations enable fast learning and rendering of dynamic radiance fields, they require a dense set of input viewpoints. In this work, we focus on learning a fast representation for dynamic radiance fields with sparse input viewpoints. However, the optimization with sparse input is under-constrained and necessitates the use of motion priors to constrain the learning. Existing fast dynamic scene models do not explicitly model the motion, making them difficult to be constrained with motion priors. We design an explicit motion model as a factorized 4D representation that is fast and can exploit the spatio-temporal correlation of the motion field. We then introduce reliable flow priors including a combination of sparse flow priors across cameras and dense flow priors within cameras to regularize our motion model. Our model is fast, compact and achieves very good performance on popular multi-view dynamic scene datasets with sparse input viewpoints. The source code for our model can be found on our project page: https://nagabhushansn95.github.io/publications/2024/RF-DeRF.html.