vcgClostKD: Project coordinates onto a target triangular surface mesh...

In zarquon42b/Rvcg: Manipulations of Triangular Meshes Based on the 'VCGLIB' API

Project coordinates onto a target triangular surface mesh using KD-tree search

Description

For a set of 3D-coordinates/triangular mesh, the closest matches on a target surface are determined (by using KD-tree search) and normals at as well as distances to that point are calculated.

Usage

vcgClostKD(
  x,
  mesh,
  sign = TRUE,
  barycentric = FALSE,
  smoothNormals = FALSE,
  borderchk = FALSE,
  k = 50,
  nofPoints = 16,
  maxDepth = 64,
  angdev = NULL,
  weightnorm = FALSE,
  facenormals = FALSE,
  threads = 1,
  ...
)

Arguments

x	k x 3 matrix containing 3D-coordinates or object of class "mesh3d".
mesh	triangular surface mesh stored as object of class "mesh3d".
sign	logical: if TRUE, signed distances are returned.
barycentric	logical: if TRUE, barycentric coordinates of the hit points are returned.
smoothNormals	logical: if TRUE, laplacian smoothed normals are used.
borderchk	logical: request checking if the hit face is at the border of the mesh.
k	integer: check the kdtree for thek closest faces (using faces' barycenters.
nofPoints	integer: number of points per cell in the kd-tree (don't change unless you know what you are doing!)
maxDepth	integer: depth of the kd-tree (don't change unless you know what you are doing!)
angdev	maximum deviation between reference and target normals. If the none of the k closest triangles match this criterion, the closest point on the closest triangle is returned but the corresponding distance in $quality is set to 1e5.
weightnorm	logical if angdev is set, this requests the normal of the closest points to be estimated by weighting the surrounding vertex normals. Otherwise, simply the hit face's normal is used (faster but slightly less accurate)
facenormals	logical: if TRUE only the facenormal of the face the closest point has hit is returned, the weighted average of the surrounding vertex normals otherwise.
threads	integer: threads to use in closest point search.
...	additional parameters, currently unused.

Value

returns an object of class "mesh3d" with:

vb	4 x n matrix containing n vertices as homolougous coordinates.
normals	4 x n matrix containing vertex normals.
quality	numeric vector containing distances to target.
it	3 x m integer matrix containing vertex indices forming triangular faces.Only available, when x is a mesh.
border	integer vector of length n: if borderchk = TRUE, for each clostest point the value will be 1 if the hit face is at the border of the target mesh and 0 otherwise.
barycoords	3 x m Matrix containing barycentric coordinates of closest points; only available if barycentric=TRUE.

Note

Other than vcgClost this does not search a grid, but first uses a KD-tree search to find the k closest barycenters for each point and then searches these faces for the closest match.

Author(s)

Stefan Schlager

References

Baerentzen, Jakob Andreas. & Aanaes, H., 2002. Generating Signed Distance Fields From Triangle Meshes. Informatics and Mathematical Modelling.

See Also

vcgPlyRead

zarquon42b/Rvcg documentation built on April 11, 2024, 3:17 a.m.