HedgehogAD: Interactive Design Exploration of Omni-Directional Aerodynamics

ABSTRACT OmniAD [Martin et al. 2015] is a data-driven pipeline for physics-based aerodynamics animations. In the pipeline, a real-time aerodynamic model which handles omni-directional airflow has also been introduced. However, their framework requires a captured motion, which implies that their model is not suitable for designing a customized motion. In this paper, we present a method to add user-controllability to the aerodynamic model in OmniAD by allowing the user to directly interact with the aerodynamics model. The system first visualizes the force and torque coefficients, which represent (x, y, z) components of aerodynamic force (i.e., drag and lift force) and torque, as a set of arrows on a sphere. The user then modifies the arrows on the screen as desired. The system updates the internal representation (parameters for spherical harmonics) and shows resulting animation. We run a user study and the participants successfully designed physically plausible falling motions using the proposed method.