shell.extract.mesh: Extract the iso-surface mesh of a volume at one level.

In fsbrain: Managing and Visualizing Brain Surface Data

Extract the iso-surface mesh of a volume at one level.

Description

The mesh is returned in the voxel space of the volume, using 1-based R array indices (i.e., the first voxel of the volume is at index 1), no matter which backend is used. Use index2ras_tkr (not vox2ras_tkr(), which expects 0-based CRS indices) to transform such a mesh to surface RAS. The result is welded and free of degenerate faces, see mesh.weld.

Usage

shell.extract.mesh(volume, level, backend)

Arguments

volume	a 3D numerical array, in voxel space.
level	numerical, the iso-level.
backend	character string, 'Rvcg' or 'misc3d'.

Value

a mesh3d instance with normals, in the voxel space of the volume, or NULL if the level is not within the range of the data.

fsbrain documentation built on Sept. 27, 2026, 1:07 a.m.