Abstract: This paper presents a sculptured solid modeling system founded upon free-form splines: (i) tri-variate B-spline solids for regular (i.e., topologically cuboid) shapes and (ii) dynamic MacCracken-Joy subdivision-based solids of arbitrary topology. Our primary contribution is that we integrate the geometry of sculptured free-form solids with the powerful physics-based modeling framework by augmenting pure geometric entities with material properties and physical behaviors. We have developed a sculpting system with an array of design tools that afford users the ability to deform and sculpt a variety of free-form solids via a three-dimensional input device.