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Case Study: SPG Optimized for Surface Files

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Fluvio L. Lobo Fenoglietto edited this page May 17, 2019 · 20 revisions

NOTES:

  • This case study was built for spg_v5
  • This case study was built as an optimized version of spg_v4
  • Follow this case study for any applications in which the input geometry consists of a surface file (.STL, .OBJ)
  • For best results, operate on (import/export) .OBJ files
  • The following guide was developed and has only been tested for Houdini 17
  • The following guide expects user familiarity with Houdini

Process

  1. Open spg_v5.hipnc using any Houdini 17 version

    1. The spg network has been set to update manually
      • We highly recommend that this option is conserved by the user
      • Certain operations in the network can highjack the computer's RAM (depending on the input model)

  2. Repeat steps 1-6 of the Case Study: Cruciforms for Biaxial Planar Mechanical Testing guide

    • The spg_v5.hipnc network looks almost identical to that of its predecessor
    • The spg_v5.hipnc network relies on surface normal inversion and merging as opposed to voxel-based volumes and boolean operations

  3. Tune Speckles Polygon Count

    • Instead of converting the speckles into a voxel-based volume, the program uses them as surfaces
    • The PolyReduce node can reduce the number of polygons describing speckles' mesh by percentage and quality
    • The polygon reduction can be mediated to ensure the preservation of important features
    • More information about the parameters of this node can be found here

Polygon Reduction Spheres

  1. Reverse Normals
    • The program calculates the inverse normals of the speckles' surface to generate corresponding cavities in the original mesh
    • The Reverse node can invert the normals of any surface mesh
    • More information about the parameters of this node can be found here

Spheres Normal Reversal

  1. Merge
    • Rather than subtracting volumes, the program combines the original surface mesh with the inverted normals of the generated speckles
    • The Merge node can combine all input surfaces in one
    • More information about the parameters of this node can be found here

Merge

  1. Export
    • Export resulting geometries using the File node in the write files configuration
    • More information about the parameters of this node can be found here
    • We recommend exporting files as .OBJ
    • We recommend that any additional file extension conversions be performed using third-party applications such as MeshLab

Comparison

  • File Size
    • 2X to 10X reduction in file size

File Size spg_v4

File Size spg_v5

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