@techreport{TR-IC-14-05,
   number = {IC-14-05},
   author  =  {Elisa  de  Cássia  Silva Rodrigues and Jorge Stolfi and
                   Anamaria Gomide},
   title  = {{Editing \textbf{$C^1$}-Continuous 2D Spline Deformations
                   by Constrained Least Squares}},
   month = {February},
   year = {2014},
   institution = {Institute of Computing, University of Campinas},
   note = {In English, 22 pages.
    \par\selectlanguage{english}\textbf{Abstract}
       We    describe    a   method   for   interactive   editing   of  
       \textbf{$C^1$}-continuous  deformations of the plane defined by
       splines  of  degree  5  on  an  arbitrary  triangular mesh. The
       continuity   constraints  and  the  user  editing  actions  are 
       combined  using  weighted and constrained least squares instead
       of  the  usual  finite  element  approach. We worked with exact
       integer   arithmetic   in   order   to   detect  and  eliminate 
       redundancies in the set of constraints. To validate our method,
       we  used  it  as  part  of  an  friendly interactive editor for
       ``2.5D''  space  deformations.  This  editor  has  been used to
       deform  3D  models of non-rigid living microscopic organisms as
       seen in actual optical microscope images.
  }
}