Three-dimensional Proxies for Hand-drawn Characters



Drawing shapes by hand and manipulating computer-generated objects are the two dominant forms of animation. Though each medium has its own advantages, the techniques developed for one medium are not easily leveraged in the other medium because hand animation is two-dimensional, and inferring the third dimension is mathematically ambiguous. A second challenge is that the character is a consistent three-dimensional (3D) object in computer animation while hand animators introduce geometric inconsistencies in the two-dimensional (2D) shapes to better convey a character's emotional state and personality. In this work, we identify 3D proxies to connect hand-drawn animation and 3D computer animation. We present an integrated approach to generate three levels of 3D proxies: single-points, polygonal shapes, and a full joint hierarchy. We demonstrate how this approach enables one medium to take advantage of techniques developed for the other; for example, 3D physical simulation is used to create clothes for a hand-animated character, and a traditionally trained animator is able to influence the performance of a 3D character while drawing with paper and pencil.

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Publications

  1. "Three-dimensional Proxies for Hand-drawn Characters", Eakta Jain, Yaser Sheikh, Moshe Mahler, Jessica Hodgins. (ACM Transactions on Graphics, January 2012)
    • Paper (PDF)
    • Video (MOV, 42M, with audio)
    • Bibtex entry:
      @article{jain:2012,
      author = {Jain, Eakta and Sheikh, Yaser and Mahler, Moshe and Hodgins, Jessica},
      title = {Three-dimensional proxies for hand-drawn characters},
      journal = {ACM Trans. Graph.},
      issue_date = {January 2012},
      volume = {31},
      number = {1},
      month = feb,
      year = {2012},
      pages = {8:1--8:16},
      articleno = {8},
      numpages = {16}
      }
      
    • Presentation slides from SIGGRAPH 2012: pdf, keynote, ppt
  2. This journal paper presents a generalization of the techniques of the following conference publications:

  3. "Augmenting Hand Animation with Three-dimensional Secondary Motion", SCA 2010 (Best Paper Award) click here
  4. "Leveraging the Talent of Hand Animators to Create Three-Dimensional Animation", SCA 2009 click here

Acknowledgements

We thank Glen Keane, Tom LaBaff and Travis Blaise for providing the input animations, and Justin Macey for help with motion capture. Thanks also to Autodesk for their donation of the 3D animation and rendering package Maya, and to Disney Research for summer funding. Partial funding was also provided by NSF CCF- 0811450 and NSF IIS-0916272.

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