vcg_uniform_remesh: Sample a surface mesh uniformly

In ravetools: Signal and Image Processing Toolbox for Analyzing Intracranial Electroencephalography Data

Sample a surface mesh uniformly

Description

Sample a surface mesh uniformly

Usage

vcg_uniform_remesh(
  x,
  voxel_size = NULL,
  offset = 0,
  discretize = FALSE,
  multi_sample = FALSE,
  absolute_distance = FALSE,
  merge_clost = FALSE,
  verbose = TRUE
)

Arguments

x	surface
voxel_size	'voxel' size for space 'discretization'
offset	offset position shift of the new surface from the input
discretize	whether to use step function(TRUE) instead of linear interpolation (FALSE) to calculate the position of the intersected edge of the marching cube; default is FALSE
multi_sample	whether to calculate multiple samples for more accurate results (at the expense of more computing time) to remove artifacts; default is FALSE
absolute_distance	whether an unsigned distance field should be computed. When set to TRUE, non-zero offsets is to be set, and double-surfaces will be built around the original surface, like a sandwich.
merge_clost	whether to merge close vertices; default is TRUE
verbose	whether to verbose the progress; default is TRUE

Value

A triangular mesh of class 'mesh3d'

Coercing Surface Inputs

The surface objects are converted to 'mesh3d' object before applying further calculations.

When surface is a surface ieegio object, the returned mesh3d$vb contains vertices that have been left-multiplied by surface$geometry$transforms[[1]] (the first transform stored in the geometry, typically the ScannerAnat or voxel-to-world transform).

Breaking change: Earlier versions (before 0.2.6) of ravetools returned the raw surface$geometry$vertices without applying any transform, so downstream code often multiplied by surface$geometry$transforms[[1]] (or an equivalent) manually before working in world space. Such code will now double apply the transform and produce incorrect coordinates. If you previously applied a transform from surface$geometry$transforms by hand after calling a ravetools mesh function on an 'ieegio_surface', remove that manual step.

Surfaces with an empty or missing geometry$transforms list (for example, surfaces produced by ieegio's volume_to_surface, which stores an identity transform) are unaffected.

If geometry$transforms contains multiple transforms targeting different coordinate spaces, only the first one is used. Callers that need a specific target space should select and apply that transform themselves before calling ravetools mesh functions.

Examples

sphere <- vcg_sphere()
mesh <- vcg_uniform_remesh(sphere, voxel_size = 0.45)

if(is_not_cran()) {

rgl_view({

  rgl_call("mfrow3d", 1, 2)

  rgl_call("title3d", "Input")
  rgl_call("wire3d", sphere, col = 2)
  rgl_call("next3d")

  rgl_call("title3d", "Re-meshed to 0.1mm edge distance")
  rgl_call("wire3d", mesh, col = 3)
})

}

ravetools documentation built on May 31, 2026, 9:06 a.m.