{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,28]],"date-time":"2026-03-28T03:15:14Z","timestamp":1774667714313,"version":"3.50.1"},"reference-count":20,"publisher":"Association for Computing Machinery (ACM)","issue":"4","license":[{"start":{"date-parts":[[2015,7,27]],"date-time":"2015-07-27T00:00:00Z","timestamp":1437955200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/www.acm.org\/publications\/policies\/copyright_policy#Background"}],"content-domain":{"domain":["dl.acm.org"],"crossmark-restriction":true},"short-container-title":["ACM Trans. Graph."],"published-print":{"date-parts":[[2015,7,27]]},"abstract":"<jats:p>\n            We present a space-time abstraction for the sketch-based design of character animation. It allows animators to draft a full coordinated motion using a single stroke called the\n            <jats:italic>space-time curve<\/jats:italic>\n            (STC). From the STC we compute a dynamic line of action (DLOA) that drives the motion of a 3D character through projective constraints. Our dynamic models for the line's motion are entirely geometric, require no pre-existing data, and allow full artistic control. The resulting DLOA can be refined by over-sketching strokes along the space-time curve, or by composing another DLOA on top leading to control over complex motions with few strokes. Additionally, the resulting dynamic line of action can be applied to arbitrary body parts or characters. To match a 3D character to the 2D line over time, we introduce a robust matching algorithm based on closed-form solutions, yielding a tight match while allowing squash and stretch of the character's skeleton. Our experiments show that space-time sketching has the potential of bringing animation design within the reach of beginners while saving time for skilled artists.\n          <\/jats:p>","DOI":"10.1145\/2766893","type":"journal-article","created":{"date-parts":[[2015,7,28]],"date-time":"2015-07-28T12:26:38Z","timestamp":1438086398000},"page":"1-10","update-policy":"https:\/\/doi.org\/10.1145\/crossmark-policy","source":"Crossref","is-referenced-by-count":46,"title":["Space-time sketching of character animation"],"prefix":"10.1145","volume":"34","author":[{"given":"Martin","family":"Guay","sequence":"first","affiliation":[{"name":"Universit\u00e9 de Grenoble LJK, INRIA"}]},{"given":"R\u00e9mi","family":"Ronfard","sequence":"additional","affiliation":[{"name":"Universit\u00e9 de Grenoble LJK, INRIA"}]},{"given":"Michael","family":"Gleicher","sequence":"additional","affiliation":[{"name":"University of Wisconsin Madison"}]},{"given":"Marie-Paule","family":"Cani","sequence":"additional","affiliation":[{"name":"Universit\u00e9 de Grenoble LJK, INRIA"}]}],"member":"320","published-online":{"date-parts":[[2015,7,27]]},"reference":[{"key":"e_1_2_2_1_1","doi-asserted-by":"publisher","DOI":"10.1145\/344779.344859"},{"key":"e_1_2_2_2_1","doi-asserted-by":"publisher","DOI":"10.1145\/360349.360357"},{"key":"e_1_2_2_3_1","volume-title":"Proceedings of the 2003 ACM SIGGRAPH\/Eurographics symposium on Computer animation, 320--328","author":"Davis J.","unstructured":"Davis , J. , Igarashi , M. , Chuang , E. , Popovic' , Z. , and Salesin , D . 2003. A sketching interface for articulated figure animation . Proceedings of the 2003 ACM SIGGRAPH\/Eurographics symposium on Computer animation, 320--328 . Davis, J., Igarashi, M., Chuang, E., Popovic', Z., and Salesin, D. 2003. A sketching interface for articulated figure animation. Proceedings of the 2003 ACM SIGGRAPH\/Eurographics symposium on Computer animation, 320--328."},{"key":"e_1_2_2_4_1","doi-asserted-by":"publisher","DOI":"10.1145\/1357054.1357122"},{"key":"e_1_2_2_5_1","doi-asserted-by":"publisher","DOI":"10.1145\/882262.882285"},{"key":"e_1_2_2_6_1","doi-asserted-by":"publisher","DOI":"10.1145\/364338.364400"},{"key":"e_1_2_2_7_1","doi-asserted-by":"publisher","DOI":"10.1145\/2508363.2508397"},{"key":"e_1_2_2_8_1","volume-title":"proceedings of the Symposium on Sketch-Based Interfaces and Modeling, SBIM '15","author":"Guay M.","unstructured":"Guay , M. , Ronfard , R. , Gleicher , M. , and Cani , M . -P. 2015. Adding dynamics to sketch-based character animations . In proceedings of the Symposium on Sketch-Based Interfaces and Modeling, SBIM '15 . Guay, M., Ronfard, R., Gleicher, M., and Cani, M.-P. 2015. Adding dynamics to sketch-based character animations. In proceedings of the Symposium on Sketch-Based Interfaces and Modeling, SBIM '15."},{"key":"e_1_2_2_9_1","doi-asserted-by":"publisher","DOI":"10.1145\/218380.218414"},{"key":"e_1_2_2_10_1","doi-asserted-by":"publisher","DOI":"10.1145\/288392.288599"},{"key":"e_1_2_2_11_1","doi-asserted-by":"publisher","DOI":"10.1145\/1053427.1053452"},{"key":"e_1_2_2_12_1","doi-asserted-by":"publisher","DOI":"10.1145\/344779.344876"},{"key":"e_1_2_2_13_1","doi-asserted-by":"publisher","DOI":"10.1145\/1640443.1640452"},{"key":"e_1_2_2_14_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1467-8659.2007.01091.x"},{"key":"e_1_2_2_15_1","doi-asserted-by":"publisher","DOI":"10.1145\/2485895.2485916"},{"key":"e_1_2_2_16_1","unstructured":"Sadasivam K. M. 2012. Learn to draw dynamic comic characters using the \"two cans\" technique! Blog post.  Sadasivam K. M. 2012. Learn to draw dynamic comic characters using the \"two cans\" technique! Blog post."},{"key":"e_1_2_2_17_1","doi-asserted-by":"publisher","DOI":"10.1145\/15922.15903"},{"key":"e_1_2_2_18_1","doi-asserted-by":"crossref","unstructured":"Shiratori T. Mahler M. Trezevant W. and Hodgins J. K. 2013. Expressing animated performances through puppeteering. IEEE 3DUI 59--66.  Shiratori T. Mahler M. Trezevant W. and Hodgins J. K. 2013. Expressing animated performances through puppeteering. IEEE 3DUI 59--66.","DOI":"10.1109\/3DUI.2013.6550198"},{"key":"e_1_2_2_19_1","doi-asserted-by":"publisher","DOI":"10.1145\/1015706.1015740"},{"key":"e_1_2_2_20_1","doi-asserted-by":"publisher","DOI":"10.1145\/1276377.1276509"}],"container-title":["ACM Transactions on Graphics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dl.acm.org\/doi\/10.1145\/2766893","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/dl.acm.org\/doi\/pdf\/10.1145\/2766893","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,6,18]],"date-time":"2025-06-18T18:56:01Z","timestamp":1750272961000},"score":1,"resource":{"primary":{"URL":"https:\/\/dl.acm.org\/doi\/10.1145\/2766893"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2015,7,27]]},"references-count":20,"journal-issue":{"issue":"4","published-print":{"date-parts":[[2015,7,27]]}},"alternative-id":["10.1145\/2766893"],"URL":"https:\/\/doi.org\/10.1145\/2766893","relation":{},"ISSN":["0730-0301","1557-7368"],"issn-type":[{"value":"0730-0301","type":"print"},{"value":"1557-7368","type":"electronic"}],"subject":[],"published":{"date-parts":[[2015,7,27]]},"assertion":[{"value":"2015-07-27","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}