attributes: Get information about shapes

Description

Retrieves information about the shapes in a scene.

Usage

rgl.attrib.count(id, attrib)
rgl.attrib(id, attrib, first = 1, 
           last = rgl.attrib.count(id, attrib))

Arguments

A shape identifier, as returned by rgl.ids.

attrib

An attribute of a shape. Currently supported: one of

c("vertices", "normals", "colors", "texcoords", "dim", "texts",
        "cex", "adj", "radii", "centers",  "ids", 
        "usermatrix", "types", "flags" )

, or unique prefixes to one

first, last

Specify these to retrieve only those rows of the result.

Value

rgl.attrib.count returns the count of the requested attribute. rgl.attrib returns the values of the attribute. Attributes are mostly real-valued, with the following sizes: [object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object] The "texts" and "types" attributes are character-valued; the flags attribute is logical valued, with named rows. These are returned as matrices with the row count equal to the count for the attribute, and the columns as listed above.

Details

If the identifier is not found or is not a shape that has the given attribute, zero will be returned by rgl.attrib.count, and an empty matrix will be returned by rgl.attrib. The first four attrib names correspond to the usual OpenGL properties; "dim" is used just for surfaces, defining the rows and columns in the rectangular grid; "cex" and "adj" apply only to text objects.

Examples

Run this code

p <- plot3d(rnorm(100), rnorm(100), rnorm(100), type="s", col="red")
rgl.attrib.count(p["data"], "vertices")
rgl.attrib(p["data"], "vertices", last=10)