A Single-View Approach to Casual 3D Modeling and Animation

publication
ACM SIGGRAPH ASIA 2020
authors
Marek Dvorožňák, Daniel Sýkora, Cassidy Curtis, Brian Curless, Olga Sorkine-Hornung, David Salesin

A selection of animated characters created using Monster Mash by animators who participated in our informal user study. For each example, the original hand-drawn outlines are visible in the inset above (superimposed over the original drawing or a source photo). From these outlines, Monster Mash can inflate a smooth, consistent 3D model that can immediately be animated using several control points (red and green dots). Their trajectories are visualised as grey curves. See our supplementary videos for these characters in motion. Colored source drawings by Hélène Leroux and Neth Nom.

abstract

We present a new framework for sketch-based modeling and animation of 3D organic shapes that can work entirely in an intuitive 2D domain, enabling a playful, casual experience. Unlike previous sketch-based tools, our approach does not require a tedious part-based multi-view workflow with the explicit specification of an animation rig. Instead, we combine 3D inflation with a novel rigidity-preserving, layered deformation model, ARAP-L, to produce a smooth 3D mesh that is immediately ready for animation. Moreover, the resulting model can be animated from a single viewpoint — and without the need to handle unwanted inter-penetrations, as required by previous approaches. We demonstrate the benefit of our approach on a variety of examples produced by inexperienced users as well as professional animators. For less experienced users, our single-view approach offers a simpler modeling and animating experience than working in a 3D environment, while for professionals, it offers a quick and casual workspace for ideation.

downloads

videos

main video

tutorial

creation process

animation example

acknowledgments

We thank the reviewers for their insightful comments and suggestions. We are also grateful to Hélène Leroux, Neth Nom, David Murphy, Samuel Leather, Pavla Sýkorová, and Jakub Javora for participating in the interactive sessions. This research was supported by Google, the Grant Agency of the Czech Technical University in Prague, grant No. SGS19/179/OHK3/3T/13 (Research of Modern Computer Graphics Methods), and by the Research Center for Informatics, grant No. CZ.02.1.01/0.0/0.0/16_019/0000765.