# Wiki

Clone wiki# PolyVox / Academic Papers on Voxels

Voxels have a wide range of uses in games and visualisation, and so have been the subject of numerous academic papers.

# Surface Extraction

Marching Cubes: A High Resolution 3D Surface Construnction Algorithm

We present a new algorithm, called marching cubes, that creates triangle models of constant density surfaces from 3D medical data. Using a divide-and-conquer approach to generate inter-slice connectivity, we create a case table that defines triangle topology. The algorithm processes the 3D medical data in scan-line order and calculates triangle vertices using linear interpolation. We find the gradient of the original data, normalize it, and use it as a basis for shading the models. The detail in images produced from the generated surface models is the result of maintaining the inter-slice connectivity, surface data, and gradient information present in the original 3D data. Results from computed tomography (CT), magnetic resonance (MR), and single-photon emission computed tomography (SPECT) illustrate the quality and functionality of marching cubes. We also discuss improvements that decrease processing time and add solid modeling capabilities.

# Converting Meshes to Volumes

Wavelet Rasterization

We present a method for analytically calculating an anti-aliased rasterization of arbitrary polygons or fonts
bounded by Bézier curves in 2D as well as oriented triangle meshes in 3D. Our algorithm rasterizes multiple
resolutions simultaneously using a hierarchical wavelet representation and is robust to degenerate inputs. We
show that using the simplest wavelet, the Haar basis, is equivalent to performing a box-filter to the rasterized image.
Because we evaluate wavelet coefficients through line integrals in 2D, we are able to derive analytic solutions
for polygons that have Bézier curve boundaries of any order, and we provide solutions for quadratic and cubic
curves. In 3D, we compute the wavelet coefficients through analytic surface integrals over triangle meshes and
show how to do so in a computationally efficient manner.

# Volume Processing

Updated