Sketch-Based Generation and Editing of Quad Meshes

publication
ACM SIGGRAPH 2013
authors
Kenshi Takayama, Daniele Panozzo, Alexander Sorkine-Hornung, Olga Sorkine-Hornung

Quads!

In our system, the user can create patches of quadrilaterals by simply sketching freeform curves, and furthermore control their topology by changing the number of edge subdivisions at the patch boundaries (a). On top of this concept, we propose several novel tools including spine sketching (b) and autocompletion (c) to make the process of sketching the curve network more efficient. Two professional artists using our system were able to create high-quality quad meshes very quickly (d).

abstract

Coarse quad meshes are the preferred representation for animating characters in movies and video games. In these scenarios, artists want explicit control over the edge flows and the singularities of the quad mesh. Despite the significant advances in recent years, existing automatic quad remeshing algorithms are not yet able to achieve the quality of manually created remeshings. We present an interactive system for manual quad remeshing that provides the user with a high degree of control while avoiding the tediousness involved in existing manual tools. With our sketch-based interface the user constructs a quad mesh by defining patches consisting of individual quads. The desired edge flow is intuitively specified by the sketched patch boundaries, and the mesh topology can be adjusted by varying the number of edge subdivisions at patch boundaries. Our system automatically inserts singularities inside patches if necessary, while providing the user with direct control of their topological and geometrical locations. We developed a set of novel user interfaces that assist the user in constructing a curve network representing such patch boundaries. The effectiveness of our system is demonstrated through a user evaluation with professional artists. Our system is also useful for editing automatically generated quad meshes.

downloads

video

acknowledgments

We are deeply grateful to Maurizio Nitti for the illuminating discussions and concept sketches that were tremendously helpful for the development of our system. We also thank Maurizio Nitti and Alessia Marra for their participation in the user evaluation and feedback. We thank Jun Saito and his colleagues for a useful discussion. We are grateful to Felix Hornung for helping us with the technical illustrations and to Emily Whiting for narrating the video. The Bunny and Armadillo models are courtesy of the Stanford 3D Scanning Repository. The Horse and Bimba models are courtesy of the AIM@SHAPE Shape Repository. The Head model is by Nick Zuccarello, provided by ZBrush©Pixologic Inc. The Hand model is from TurboSquid. Other models are kindly provided by Maurizio Nitti. This work was supported in part by the ERC grant iModel (StG-2012-306877), by an SNF award 200021_137879 and by a gift from Adobe Research. Kenshi Takayama's stay at ETH Zurich is funded by JSPS Postdoctoral Fellowships for Research Abroad.