Response to Reviewer Jp9x
**Q1: Some modules are not that novel from a technical perspective. E.g., the transformer block is also explored in GEN-2. LORA and adapter are also commonly used in various personalization papers.**
As motivated in Sec. 1, our primary goal is to develop an effective pipeline to animate personalized T2I models. The technical novelty of our work is not in the modules themselves, but in the unique way they are combined and utilized, leading to an innovative solution that is greater than simply putting them together.
And it is not ad-hoc to use these two modules. In Sec. 5.3 and Sec. 4.2, we investigate different options for the motion module, e.g., a convolution version, and it turns out the current simple design is strong and efficient. In terms of the domain adapter, as discussed in Sec. 4.1 and Sec. 5.3, it's worth noting that we didn't use it for domain personalization as in previous work. Instead, we only use it during training to reduce the gap between video training data and high-quality training images of T2I. This not only results in high-quality video generation but also offers a new usage of domain adapters.
**Q2: The paper somewhat overlooks a thorough discussion of the method's limitations.**
We have added a section in the revised submission to discuss the limitations of our method (see pages 22-23, Appendix D). We address the concerns in [W2] in the following Q3-Q5.
**Q3: About the learning dynamics of the motion module when pre-trained on the WebVid dataset.**
AnimateDiff utilizes data priors to learn motions in the training videos dataset WebVid-10M, which contains mainly real-world footage such as outdoor scenes and human activities. By training upon it, the motion module could learn common real-world motion patterns, e.g., ocean waves, the movement of cars and boats, and human body/hand motions, as shown in Fig. 1. We have already updated the related discussion in Appendix D.1.
**Q4: About the learning of MotionLoRA and whether the motion patterns can be inferred from text clues.**
In AnimateDiff, whether a kind of motion can be triggered via text prompt depends on whether the training dataset accurately labeled such motion. We investigate the WebVid-10M dataset and find its motion labels very coarse. For instance, the zoom-in and zoom-out videos in WebVid are mostly labeled with a single tag, “zooming.” As a result, using text hints such as “zoom in” results in both zoom-in and zoom-out generation. On the other hand, more complex motion patterns such as “Rolling” do not have a specific text label, and thus, these motion patterns cannot be triggered via simple textual clues.
This observation suggests that MotionLoRA does not learn new motion patterns entirely from scratch but refines and enhances the pre-existing motion priors (regardless of whether they can be triggered by text) obtained during pre-training. It thus enables the motion module to express the desired motion priors at inference. We have already updated the related discussion in Appendix D.1.
**Q5: About the performance on different motion categories.**
In practice, we find the pipeline works well on non-violent motions such as fluid (e.g., ocean waves, fog, etc.), rigid objects (e.g., cars, boats), and simple human movements (e.g., walking, facial expressions), as shown in Fig. 1,4,9. However, if the pipeline is instructed to generate complex or rare motions rarely seen in the training dataset, e.g., dance or camera movements with drastic scene change, the model will likely generate static animation or unnatural deformations. We have already updated the related discussion in Appendix D.1.