Figure 1: Examples of three different shape-from-operator problems considered in the paper. Left: shape analogy synthesis as shape-from-difference operator problem (shape X is synthesized such that the intrinsic difference operator between C, X is as close as possible to the difference between A, B). Center: style transfer as shape-from-Laplacian problem. The Laplacian of the leftmost shape (fat man) captures the style, while the initial thin man shape (middle) captures the pose. Right: we deform the human shape (bottom leftmost) such that its Laplacian is diagonalized by the first 10 eigenfunctions of the alien Laplacian (top row). The result (bottom rightmost) is an 'intrinsic hybrid' between the two shapes.
AbstractWe formulate the problem of shape-from-operator (SfO), recovering an embedding of a mesh from intrinsic operators defined through the discrete metric (edge lengths). Particularly interesting instances of our SfO problem include: shape-from-Laplacian, allowing to transfer style between shapes; shape-from-difference operator, used to synthesize shape analogies; and shape-from-eigenvectors, allowing to generate 'intrinsic averages' of shape collections. Numerically, we approach the SfO problem by splitting it into two optimization sub-problems: metric-from-operator (reconstruction of the discrete metric from the intrinsic operator) and embedding-from-metric (finding a shape embedding that would realize a given metric, a setting of the multidimensional scaling problem). We study numerical properties of our problem, exemplify it on several applications, and discuss its imitations.