Figure 1: We introduce a method for reduced-order shape optimization of 2-manifolds that uses offset surfaces to deform the shape. Left: a bottle model is generated using offset surfaces with constant offsets. The resulting object is unable to stand. Center: the offsets are optimized such that the bottle can stand if empty, however, if filled it is unstable. Right: the model is optimized to stand both empty and filled. In order to account for that, offset surfaces are added inside and outside of the original shape. Given the 2-manifold surface of a 3d object, we propose a novel method for the computation of an offset surface with varying thickness such that the solid volume between the surface and its offset satisfies a set of prescribed constraints and at the same time minimizes a given objective functional. Since the constraints as well as the objective functional can easily be adjusted to specific application requirements, our method provides a flexible and powerful tool for shape optimization. We use manifold harmonics to derive a reduced-order formulation of the optimization problem, which guarantees a smooth offset surface and speeds up the computation independently from the input mesh resolution without affecting the quality of the result. The constrained optimization problem can be solved in a numerically robust manner with commodity solvers. Furthermore, the method allows simultaneously optimizing an inner and an outer offset in order to increase the degrees of freedom. We demonstrate our method in a number of examples where we control the physical mass properties of rigid objects for the purpose of 3d printing.
Offset surfaces can be used for shape optimization, e.g., to optimize weight distribution inside an object REF .
Reduced-order shape optimization using offset surfaces
TOGS
Computer Science