mesh2d: Convert a 2D Delaunay triangulation to a 'rgl' mesh

In stla/RCGAL: An Incomplete Wrapper of the 'CGAL' C++ Library

Convert a 2D Delaunay triangulation to a 'rgl' mesh

Description

Makes a 'rgl' mesh (mesh3d object) from a 2D Delaunay triangulation, unconstrained or constrained.

Usage

mesh2d(triangulation)

Arguments

triangulation

an output of delaunay executed with 2D points

Value

A list with three fields; mesh, a mesh3d object, borderEdges, a numeric matrix that can be used with segments3d to plot the border edges, and constraintEdges, a numeric matrix that can be used with segments3d to plot the constraint edges which are not border edges.

See Also

plotDelaunay2D

Examples

library(RCGAL)
# outer and inner hexagons ####
nsides <- 6L
angles <- seq(0, 2*pi, length.out = nsides+1L)[-1L]
outer_points <- cbind(cos(angles), sin(angles))
inner_points <- outer_points / 2
points <- rbind(outer_points, inner_points)
# constraint edges
indices <- 1L:nsides
edges <- cbind(
  indices, c(indices[-1L], indices[1L])
)
edges <- rbind(edges, edges + nsides)
# constrained Delaunay triangulation
del <- delaunay(points, constraints = edges)
# mesh
m2d <- mesh2d(del)
mesh <- m2d[["mesh"]]
# plot all edges with `wire3d`
library(rgl)
open3d(windowRect = c(100, 100, 612, 612))
shade3d(mesh, color = "red", specular = "orangered")
wire3d(mesh, color = "black", lwd = 3, specular = "black")
# plot only the border edges
open3d(windowRect = c(100, 100, 612, 612))
shade3d(mesh, color = "darkred", specular = "firebrick")
segments3d(m2d[["borderEdges"]], lwd = 3)

stla/RCGAL documentation built on June 15, 2022, 6:45 a.m.