surface3d: add height-field surface shape

In rgl: 3D Visualization Using OpenGL

Description

Adds a surface to the current scene. The surface is defined by a matrix defining the height of each grid point and two vectors defining the grid.

Usage

surface3d(x, y, z, ..., normal_x = NULL, normal_y = NULL, normal_z = NULL)
terrain3d(x, y, z, ..., normal_x = NULL, normal_y = NULL, normal_z = NULL)

Arguments

x	values corresponding to rows of z, or matrix of x coordinates
y	values corresponding to the columns of z, or matrix of y coordinates
z	matrix of heights
...	Material and texture properties. See rgl.material for details.
normal_x, normal_y, normal_z	matrices of the same dimension as z giving the coordinates of normals at each grid point

Details

Adds a surface mesh to the current scene. The surface is defined by the matrix of height values in z, with rows corresponding to the values in x and columns corresponding to the values in y. This is the same parametrization as used in persp.

If the x or y argument is a matrix, then it must be of the same dimension as z, and the values in the matrix will be used for the corresponding coordinates. This is used to plot shapes such as cylinders where z is not a function of x and y.

If the normals are not supplied, they will be calculated automatically based on neighbouring points.

surface3d always draws the surface with the ‘front’ upwards (i.e. towards higher z values). This can be used to render the top and bottom differently; see rgl.material and the example below.

For more flexibility in defining the surface, use rgl.surface.

surface3d and terrain3d are synonyms.

See Also

rgl.material, rgl.surface. See persp3d for a higher level interface.

Examples

#
# volcano example taken from "persp"
#

data(volcano)

z <- 2 * volcano        # Exaggerate the relief

x <- 10 * (1:nrow(z))   # 10 meter spacing (S to N)
y <- 10 * (1:ncol(z))   # 10 meter spacing (E to W)

zlim <- range(z)
zlen <- zlim[2] - zlim[1] + 1

colorlut <- terrain.colors(zlen) # height color lookup table

col <- colorlut[ z - zlim[1] + 1 ] # assign colors to heights for each point

open3d()
surface3d(x, y, z, color = col, back = "lines")

rgl documentation built on Feb. 1, 2021, 3:01 a.m.