Postprocessing of Voxel-Based Topologies for Additive Manufacturing Using the Computational Geometry Algorithms Library (CGAL)

Abstract

Postprocessing of 3-dimensional (3-D) topologies that are defined as a set of voxels using the Computational Geometry Algorithms Library (CGAL) is discussed. Most topology optimization algorithms return results in a 3-D voxel or 2-dimensional (2-D) pixel representation, which cannot be directly used for additive manufacturing (AM). AM typically uses a surface description of the topology in the stereolithography (STL) format, discretized using triangles. As such, any results from voxel-based topology optimization algorithms must be post-processed before 3-D printing. CGAL is a set of computational geometry algorithms, several of which are suited to the task. The work flow described in this report involves first defining a set of points in space from the voxels, either using their center points or corners. Next, a surface is generated by computing an -hull of the point set. Next, surface simplification can be used to reduce the complexity of the surface without losing any detail. Finally, surface subdivision algorithms, such as Catmull-Clark or Doo-Sabin, can be used to smooth the resulting surface.

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 2015
Accession Number
ADA618594

Entities

People

  • Raymond A. Wildman

Organizations

  • United States Army Research Laboratory

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Additive Manufacturing
  • Additives (Chemicals)
  • Algorithms
  • Geometry
  • Manufacturing
  • Military Research
  • Modulus Of Elasticity
  • Optimization
  • Point Clouds
  • Printing
  • Stereolithography
  • Three Dimensional
  • Topology
  • Topology Optimization
  • Two Dimensional

Fields of Study

  • Computer science

Readers

  • Graph Algorithms and Convex Optimization.
  • Image Processing and Computer Vision.
  • Manufacturing Engineering.

Technology Areas

  • Space