Mutable elastic models for sculpting structured shapes

Antoine Milliez (1, 2) , Michael Wand (2, 3) , Marie-Paule Cani (1) , Hans-Peter Seidel (2)

1 IMAGINE - Intuitive Modeling and Animation for Interactive Graphics & Narrative Environments
2 MPII - Max-Planck-Institut für Informatik
3 Saarland University [Saarbrücken]

In this paper, we propose a new paradigm for free-form shape deformation. Standard deformable models minimize an energy measuring the distance to a single target shape. We propose a new, "mutable" elastic model. It represents complex geometry by a collection of parts and measures the distance of each part measures to a larger set of alternative rest configurations. By detecting and reacting to local switches between best-matching rest states, we build a 3D sculpting system: It takes a structured shape consisting of parts and replacement rules as input. The shape can subsequently be elongated, compressed, bent, cut, and merged within a constraints-based free-form editing interface, where alternative rest-states model to such changes. In practical experiments, we show that the approach yields a surprisingly intuitive and easy to implement interface for interactively designing objects described by such discrete shape grammars, for which direct shape control mechanisms were typically lacking.

Mots clés: Shape; Interaction

Domaines: Synthèse d'image et réalité virtuelle [cs.GR]

Antoine Milliez, Michael Wand, Marie-Paule Cani, Hans-Peter Seidel. Mutable elastic models for sculpting structured shapes. Computer Graphics Forum, 2013, 32 (2pt1), pp.21-30. ⟨10.1111/cgf.12022⟩. ⟨hal-00797189v2⟩