Uni3C: Unifying Precisely 3D-Enhanced Camera and Human Motion Controls
  for Video Generation
Authors: name: Chenjie Cao; name: Jingkai Zhou; name: Shikai Li; name: Jingyun Liang; name: Chaohui Yu; name: Fan Wang; name: Xiangyang Xue; name: Yanwei Fu
Published: 2025-04-21 07:10:41

Abstract: Camera and human motion controls have been extensively studied for video
generation, but existing approaches typically address them separately,
suffering from limited data with high-quality annotations for both aspects. To
overcome this, we present Uni3C, a unified 3D-enhanced framework for precise
control of both camera and human motion in video generation. Uni3C includes two
key contributions. First, we propose a plug-and-play control module trained
with a frozen video generative backbone, PCDController, which utilizes
unprojected point clouds from monocular depth to achieve accurate camera
control. By leveraging the strong 3D priors of point clouds and the powerful
capacities of video foundational models, PCDController shows impressive
generalization, performing well regardless of whether the inference backbone is
frozen or fine-tuned. This flexibility enables different modules of Uni3C to be
trained in specific domains, i.e., either camera control or human motion
control, reducing the dependency on jointly annotated data. Second, we propose
a jointly aligned 3D world guidance for the inference phase that seamlessly
integrates both scenic point clouds and SMPL-X characters to unify the control
signals for camera and human motion, respectively. Extensive experiments
confirm that PCDController enjoys strong robustness in driving camera motion
for fine-tuned backbones of video generation. Uni3C substantially outperforms
competitors in both camera controllability and human motion quality.
Additionally, we collect tailored validation sets featuring challenging camera
movements and human actions to validate the effectiveness of our method.