This function takes a description of a flat polygon in x, y and z coordinates, and draws it in three dimensions.

polygon3d(x, y = NULL, z = NULL, fill = TRUE, plot = TRUE, 
          coords = 1:2, random = TRUE, ...)


x, y, z

Vertices of the polygon in a form accepted by xyz.coords.


logical; should the polygon be filled?


logical; should the polygon be displayed?


Which two coordinates (x = 1, y = 2, z = 3) describe the polygon.


Should a random triangulation be used?


Other parameters to pass to lines3d or shade3d if plot = TRUE.


The function triangulates the two dimensional polygon described by coords, then applies the triangulation to all three coordinates. No check is made that the polygon is actually all in one plane, but the results may be somewhat unpredictable (especially if random = TRUE) if it is not.

Polygons need not be simple; use NA to indicate separate closed pieces. For fill = FALSE there are no other restrictions on the pieces, but for fill = TRUE the resulting two-dimensional polygon needs to be one that triangulate can handle.


If plot = TRUE, the id number of the lines (for fill = FALSE) or triangles (for fill = TRUE) that have been plotted.

If plot = FALSE, then for fill = FALSE, a vector of indices into the XYZ matrix that could be used to draw the polygon. For fill = TRUE, a triangular mesh object representing the triangulation.


Duncan Murdoch

See also

extrude3d for a solid extrusion of a polygon, triangulate for the triangulation.


theta <- seq(0, 4*pi, len = 50)
r <- theta + 1
r <- c(r[-50], rev(theta*0.8) + 1)
theta <- c(theta[-50], rev(theta))
x <- r*cos(theta)
y <- r*sin(theta)
plot(x, y, type = "n")
polygon(x, y)

polygon3d(x, y, x + y, col = "blue")