vcg_smooth: Implicitly smooth a triangular mesh

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

Implicitly smooth a triangular mesh

Description

Applies smoothing algorithms on a triangular mesh.

Usage

vcg_smooth_implicit(
  mesh,
  lambda = 0.2,
  use_mass_matrix = TRUE,
  fix_border = FALSE,
  use_cot_weight = FALSE,
  degree = 1L,
  laplacian_weight = 1
)

vcg_smooth_explicit(
  mesh,
  type = c("taubin", "laplace", "HClaplace", "fujiLaplace", "angWeight",
    "surfPreserveLaplace"),
  iteration = 10,
  lambda = 0.5,
  mu = -0.53,
  delta = 0.1
)

Arguments

mesh	triangular mesh stored as object of class 'mesh3d'.
lambda	In vcg_smooth_implicit, the amount of smoothness, useful only if use_mass_matrix is TRUE; default is 0.2. In vcg_smooth_explicit, parameter for 'taubin' smoothing.
use_mass_matrix	logical: whether to use mass matrix to keep the mesh close to its original position (weighted per area distributed on vertices); default is TRUE
fix_border	logical: whether to fix the border vertices of the mesh; default is FALSE
use_cot_weight	logical: whether to use cotangent weight; default is FALSE (using uniform 'Laplacian')
degree	integer: degrees of 'Laplacian'; default is 1
laplacian_weight	numeric: weight when use_cot_weight is FALSE; default is 1.0
type	method name of explicit smooth, choices are 'taubin', 'laplace', 'HClaplace', 'fujiLaplace', 'angWeight', 'surfPreserveLaplace'.
iteration	number of iterations
mu	parameter for 'taubin' explicit smoothing.
delta	parameter for scale-dependent 'Laplacian' smoothing or maximum allowed angle (in 'Radian') for deviation between surface preserving 'Laplacian'.

Value

An object of class "mesh3d" with:

vb	vertex coordinates
normals	vertex normal vectors
it	triangular face index

Examples

if(is_not_cran()) {

# Prepare mesh with no normals
data("left_hippocampus_mask")

# Grow 2mm on each direction to fill holes
volume <- grow_volume(left_hippocampus_mask, 2)

# Initial mesh
mesh <- vcg_isosurface(volume)

# Start: examples
rgl_view({
  rgl_call("mfrow3d", 2, 4)
  rgl_call("title3d", "Naive ISOSurface")
  rgl_call("shade3d", mesh, col = 2)

  rgl_call("next3d")
  rgl_call("title3d", "Implicit Smooth")
  rgl_call("shade3d", col = 2,
           x = vcg_smooth_implicit(mesh, degree = 2))

  rgl_call("next3d")
  rgl_call("title3d", "Explicit Smooth - taubin")
  rgl_call("shade3d", col = 2,
           x = vcg_smooth_explicit(mesh, "taubin"))

  rgl_call("next3d")
  rgl_call("title3d", "Explicit Smooth - laplace")
  rgl_call("shade3d", col = 2,
           x = vcg_smooth_explicit(mesh, "laplace"))

  rgl_call("next3d")
  rgl_call("title3d", "Explicit Smooth - angWeight")
  rgl_call("shade3d", col = 2,
           x = vcg_smooth_explicit(mesh, "angWeight"))

  rgl_call("next3d")
  rgl_call("title3d", "Explicit Smooth - HClaplace")
  rgl_call("shade3d", col = 2,
           x = vcg_smooth_explicit(mesh, "HClaplace"))

  rgl_call("next3d")
  rgl_call("title3d", "Explicit Smooth - fujiLaplace")
  rgl_call("shade3d", col = 2,
           x = vcg_smooth_explicit(mesh, "fujiLaplace"))

  rgl_call("next3d")
  rgl_call("title3d", "Explicit Smooth - surfPreserveLaplace")
  rgl_call("shade3d", col = 2,
           x = vcg_smooth_explicit(mesh, "surfPreserveLaplace"))
})

}

ravetools documentation built on Sept. 11, 2024, 9:06 p.m.