1. Abstract
   1. transforms an input line drawing into an image of a fractured surface
      1. example
   2. Voronoi diagram based
   3. interpret region boundaries as cracks
2. Introduction
   1. Non-photorealistic rendering(NPR)
      1. goals
         1. producing a recognizable representative of the phenomenon in question
         2. being controllable enough that an artist’s vision can be realized
   2. Our method
      1. uses a modified form of the Voronoi diagram
3. Background
4. Basic fracture algorithm
   1. basis
      1. Voronoi diagram
      2. use path distance through a graph
   2. Our graph
      1. a regular 4-connected lattice where each node is a texture pixel
      2. have a set of noise values{N}
         1. each node i has a corresponding value Ni
      3. Comparison between the regular Voronoi dia- gram and the noise-Voronoi diagram
   3. Implementation notes
      1. breadth-first search
      2. we have a “frontier”
         1. implementing the frontier as a heap
   4. Crack widths
      1. have some variation in crack widths
      2. multiscale cracking
         1. earlier, more widely spaced cracks divide regions containing smaller and more closely spaced cracks.
         2. Basic cracking algorithm
      3. example
         1. Some cracked words
5. Controlling crack placement
   1. image-guided cracks
      1. edges which lie within the foreground of the image have their costs increased by some quantity
   2. Fracture distribution
6. Rendering
   1. texture transfer(more visually pleasing)
      1. Hertzmann et al. [3]
      2. input
         1. photographs of cracked materials
      3. output
         1. a binary image specifying each pixel as crack or non-crack
   2. or
   3. texture modulation(faster)
7. Animation
   1. Dynamic image content
   2. or
   3. Fracture expansion