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Downsample Vertex Geometry

Group (Subgroup)

Sampling (Geometry)

Description

This Filter downsamples (i.e., reduces the number of points in) an input Vertex Geometry. Three approaches for downsampling are provided by the Filter:

  • Remove every Nth point:
    • Each Nth point, in the order the points are stored, is removed from the Vertex Geometry. The parameter N is set by the user. For example, if N=2, half of the points in the Vertex Geometry would be removed.
  • Remove a fixed fraction of random points:
    • A user-defined fraction of points are removed at random from the Vertex Geometry. For example, if the user selects a fraction of 0.2, 20% of the points would be removed from the Vertex Geometry at random.
  • Downsample the geometry on a grid:
    • The user defines the resolution (i.e., voxel spacing) of a structure rectilinear grid. This sampling grid is overlaid on the Vertex Geoemtry. All points that fall in a given voxel are averaged together, producing a single point at each voxel whose (x,y,z) coordinates are the mean of the coordinates of all points in that voxel. Additionally, any Attribute Arrays that exist on these points are averaged together within each sampling voxel.

Note that the Vertex Geometry is modified in place.

Parameters

Name Type Description
Downsample Type Enumeration The downsampling approach to use, either Remove Every Nth Point, Remove a Fixed Random Fraction of Points, or Downsample the Geometry on a Grid
Decimation Frequency int The cadence at which to remove points, if Remove Every Nth Point is chosen
Fraction to Remove float The fraction of points to remove, if Remove a Fixed Random Fraction of Points is chosen
Grid Resolution float 3x The resolution of the downsampling grid, if Downsample the Geometry on a Grid is chosen

Required Geometry

Vertex

Required Objects

Kind Default Name Type Component Dimensions Description
Data Container None N/A N/A Data Container holding the Vertex Geometry to downsample

Created Objects

None

Please see the description file distributed with this plugin.

DREAM3D Mailing Lists

If you need more help with a filter, please consider asking your question on the DREAM3D Users mailing list: https://groups.google.com/forum/?hl=en#!forum/dream3d-users