Generate extrusion mesh

Given a two-dimensional polygon, this generates a three-dimensional extrusion of the shape by triangulating the polygon and creating a cylinder with that shape as the end faces.

extrude3d(x, y = NULL, thickness = 1, smooth = FALSE, ...)

Arguments

x, y

A polygon description in one of the forms supported by triangulate.

thickness

The extrusion will have this thickness.

smooth

logical; should normals be added so that the edges of the extrusion appear smooth?

...

Other parameters to pass to tmesh3d when constructing the mesh.

Details

The extrusion is always constructed with the polygon in the xy plane at z = 0 and another copy at z = thickness. Use the transformation functions (e.g. rotate3d) to obtain other orientations and placements.

Value

A mesh object containing a triangulation of the polygon for each face, and quadrilaterals for the sides.

Author

Duncan Murdoch

See also

polygon3d for a simple polygon, triangulate for the triangulation, turn3d for a solid of rotation.

Examples

x <- c(1:10, 10:1)
y <- rev(c(rep(c(0, 2), 5), rep(c(1.5, -0.5), 5)))
plot(x, y, type = "n")
polygon(x, y)

open3d()
shade3d( extrude3d(x, y), col = "red" )