fm_subdivide: Split triangles of a mesh into subtriangles

In finnlindgren/fmesher: Triangle Meshes and Related Geometry Tools

Split triangles of a mesh into subtriangles

Description

Splits each mesh triangle into (n + 1)^2 subtriangles. The current version drops any edge constraint information from the mesh.

Usage

fm_subdivide(mesh, n = 1, delaunay = FALSE)

Arguments

mesh	an fm_mesh_2d object
n	number of added points along each edge. Default is 1.
delaunay	logical; if TRUE, the subdivided mesh is forced into a Delaunay triangle structure. If FALSE (default), the triangles are subdivided uniformly instead.

Value

A refined fm_mesh_2d object, with added bary information (an fm_bary() object), that can be used for interpolating functions from the original mesh to the new mesh (from version ⁠0.5.0.9002⁠).

Author(s)

Finn Lindgren [e-mail]

Examples

mesh <- fm_rcdt_2d_inla(
  loc = rbind(c(0, 0), c(1, 0), c(0, 1)),
  tv = rbind(c(1, 2, 3))
)
mesh_sub <- fm_subdivide(mesh, 3)
mesh
mesh_sub

# Difference should be zero for flat triangle meshes:
sum((mesh_sub$loc - fm_basis(mesh, mesh_sub$bary) %*% mesh$loc)^2)

plot(mesh_sub, edge.color = 2)

plot(fm_subdivide(fmexample$mesh, 3), edge.color = 2)
plot(fmexample$mesh, add = TRUE, edge.color = 1)

finnlindgren/fmesher documentation built on July 17, 2025, 1:04 a.m.