author = "Liesenfeld, Rog{\'e}rio L. W. and Stolfi, Jorge",
                title = "Dynamic animation of elastic bodies",
            booktitle = "Anais...",
                 year = "1996",
               editor = "Velho, Luiz and Albuquerque, Arnaldo de and Lotufo, Roberto A.",
                pages = "265--272",
         organization = "Simp{\'o}sio Brasileiro de Computa{\c{c}}{\~a}o Gr{\'a}fica e 
                         Processamento de Imagens, 9. (SIBGRAPI)",
            publisher = "Sociedade Brasileira de Computa{\c{c}}{\~a}o",
              address = "Porto Alegre",
             abstract = "We describe an animation system that simulates the dynamics of 
                         viscoelastic bodies subject to equality and inequality 
                         constraints. The equations of motion are derived from Lagrange's 
                         equation, and constraint forces are computed by the method of 
                         Lagrange multipliers. Each elastic body is modeled as a collection 
                         of tetrahedral finite elements whose deformation is restricted to 
                         affine transformations of their rest shapes. We use an original 
                         non-linear formula for the elastic forces, especially devised to 
                         prevent elements from collapsing to zero or negative volume. We 
                         also describe a general algorithm to detect violation of 
                         inequality constraints. For collisions, in particular, we use the 
                         optimization technique of Lin and Manocha to cut the detection 
                         time from quadratic to almost linear. Collisions are handled by 
                         temporary contact springs.",
  conference-location = "Caxambu",
      conference-year = "29 out. - 1 nov. 1996",
                 isbn = "85-244-0103-6",
             language = "en",
         organisation = "SBC - Sociedade Brasileira de Computa{\c{c}}{\~a}o; UFMG - 
                         Universidade Federal de Minas Gerais",
                  ibi = "83LX3pFwXQZW44Lb/d4TUp",
                  url = "",
           targetfile = "a82.pdf",
                 type = "Anima{\c{c}}{\~a}o e Multim{\'{\i}}dia",
        urlaccessdate = "2021, Dec. 03"