1. federl's dissertation
2. The mass-spring model
   1. Mass-spring model
   2. shortcomings
3. introduction
   1. goal
   2. Model of a growing tree trunk
   3. previous work
      1. crack formation and propagation
         1. The Skjeltorp and Meakin model
      2. image synthesis purposes
         1. Federl and Prusinkiewicz [2]
         2. Hirota et al. [5]
         3. Hirota et al. extended their previous model to volumes in [6]
      3. Other mechanically-based models
         1. Norton et al. [10]
         2. O’Brien and Hodgins [11][12]
         3. Gobron and Chiba [3]
         4. Neff and Fiume [9]
         5. Mazarak et al. [8]
      4. “less suitable for the precise description of the physical characteristic than the finite element method”
      5. this paper
         1. expand on
            1. Skjeltorp and Meakin [18]
            2. Hirota et al. [5][6]
         2. mass-spring discretization of the material
         3. adaptive finite-element discretization
4. The finite element model
   1. pseudocode
   2. Surface discretization
      1. using 6-node wedge elements
      2. procedure
         1. begins with a random distribution of points over the surface area
         2. particle repelling technique [4]
         3. construct a polygon mesh
         4. The wedges are constructed by extruding the triangles
   3. Computational representation of the discretized material layer
      1. Fundamental notions
      2. Calculation of the global stiffness matrix
   4. Stress calculation
   5. Fracture modelling by element removal
   6. Dynamic subdivision
      1. general idea
      2. Rivara and Inostroza [15].