Free-Form Deformation Axis Aligned Bounding Box

We present a new efficient collision-handling technique of free-form deformation (FFD) of an embedded surface. By adapting FFD, modeling deformation has been substantially simplified to make possible interactive rate animation of a deformable object even for a complex embedded mesh. However, the lack of effective collision detection and resolution schemes for an FFD-embedded surface hinders the overall performance and often becomes a bottleneck. Most existing collision handling techniques can be directly applied to an FFD grid for fast computation, but surface approximation error would be apparent and it could cause noticeable visual artifacts. On the other hand, applying collision detection and resolution techniques directly to the embedded surface is extremely expensive and can obliterate the viability of real-time FFD simulation because the embedded surface has a high resolution in most cases. We present a fast collision detection and resolution method for the embedded surface in an FFD-enhanced simulation maintaining the approximation error of the embedded surface. Our techniques for detection and resolution provide an ability to balance speed and quality.