ARTUS: Articulated Joint Latents under Structural Control for Object Generation

Interactive 3D assets require part geometry, connectivity and joint motion to describe the same object across changing poses. Learning their joint distribution is difficult because compact kinematic attributes and dense geometric features play different representational roles. A joint latent representation allows kinematic structure and part geometry to interact, but leaves the direction and timing of their interaction unspecified. If geometry is mixed in early, surface variation can affect the structural path representation before joint reasoning. If geometry is kept out entirely, generated geometry cannot inform subsequent hierarchy and joint-state predictions. We propose ARTUS, a joint latent model that addresses this tension through structure-controlled joint latent refinement, where kinematic structure governs the coordination of structural and geometric information. ARTUS encodes each root-to-node structural path and uses its representation to gate geometric features before joint reasoning. The resulting joint latent supports coordinated prediction of part kinematics and geometry. To incorporate realized geometry into subsequent predictions, ARTUS introduces articulation-pathway-coupled latent refinement, where the pathway-conditioned coarse geometry latent is partially noised and then refined by a frozen text-conditioned prior. The refined latent is reintegrated into the Existing Articulation Pathway for subsequent joint reasoning. Together, these components preserve structural control through gated fusion while allowing realized geometry to progressively update the articulation pathway for later predictions. Experiments on PartNet-Mobility and PM-Openable compare ARTUS with representative baselines spanning full fusion, fully staged generation, and structure–geometry latent fusion, and dissect the design through latent-construction ablations and refinement–feedback controls across surface fidelity, articulated layout, text consistency and motion compatibility measures. Code is available at https://anonymous.4open.science/r/ARTUS-4D68.