attributes: Get information about shapes

In rgl: 3D Visualization Using OpenGL

Get information about shapes

Description

Retrieves information about the shapes in a scene.

Usage

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

Arguments

id	A shape identifier, as returned by ids3d.
attrib	An attribute of a shape. Currently supported: one of "vertices", "normals", "colors", "texcoords", "dim", "texts", "cex", "adj", "radii", "centers", "ids", "usermatrix", "types", "flags", "offsets", "family", "font", "pos" or unique prefixes to one of those.
first, last	Specify these to retrieve only those rows of the result.

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", "adj", "family", "font" and "pos" apply only to text objects.

Value

rgl.attrib returns the values of the attribute. Attributes are mostly real-valued, with the following sizes:

"vertices"	3 values	x, y, z
"normals"	3 values	x, y, z
"centers"	3 values	x, y, z
"colors"	4 values	r, g, b, a
"texcoords"	2 values	s, t
"dim"	2 values	r, c
"cex"	1 value	cex
"adj"	2 values	x, y
"radii"	1 value	r
"ids"	1 value	id
"usermatrix"	4 values	x, y, z, w
"texts"	1 value	text
"types"	1 value	type
"flags"	1 value	flag
"family"	1 value	family
"font"	1 value	font
"pos"	1 value	pos

The "texts", "types" and "family" 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.

Author(s)

Duncan Murdoch

See Also

ids3d, rgl.attrib.info

Examples

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

rgl documentation built on July 9, 2023, 7:36 p.m.