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Adds text to the scene. The text is positioned in 3D space. Text is always oriented towards the camera.
rgl.texts(x, y = NULL, z = NULL, text,
adj = 0.5, pos = NULL, offset = 0.5,
family = par3d("family"), font = par3d("font"),
cex = par3d("cex"), useFreeType = par3d("useFreeType"), ...)
text3d(x, y = NULL, z = NULL, texts, adj = 0.5, pos = NULL, offset = 0.5,
usePlotmath = is.language(texts), ...)
texts3d(x, y = NULL, z = NULL, texts, adj = 0.5, pos = NULL, offset = 0.5,
usePlotmath = is.language(texts), ...)
rglFonts(...)point coordinates. Any reasonable way of defining the
coordinates is acceptable. See the function xyz.coords
for details.
text character vector to draw
text character vector to draw
one value specifying the horizontal adjustment, or two, specifying horizontal and vertical adjustment respectively.
a position specifier for the text. If specified, this
overrides any adj value given. Values of 1, 2, 3 and 4, respectively indicate positions below, to the left of, above and to the right of the specified coordinates.
when pos is specified, this value gives the offset of the label from the specified coordinate in fractions of a character width.
A device-independent font family name, or ""
A numeric font number from 1 to 5
A numeric character expansion value
logical. Should FreeType be used to draw text? (See details below.)
logical. Should plotmath3d be used for the text?
In rgl.texts, material properties; see rgl.material for details.
In rglFonts, device dependent font definitions for use with FreeType.
In the other functions, additional parameters to pass to rgl.texts.
The text drawing functions return the object ID of the text object (or sprites, in case of usePlotmath = TRUE)
invisibly.
rglFonts returns the current set of font definitions.
Fonts are specified using the family, font, cex,
and useFreeType arguments. Defaults for the currently active
device may be set using par3d, or for future devices
using r3dDefaults.
The family specification is the same as for standard graphics, i.e.
families
c("serif", "sans", "mono", "symbol")
are normally
available, but users may add additional families. font numbers
are restricted to the range 1 to 4 for standard, bold, italic and bold italic
respectively; with font 5 recoded as family "symbol" font 1.
Using an unrecognized value for "family" will result in
the system standard font as used in rgl up to version 0.76. That font
is not resizable and font values are ignored.
If useFreeType is TRUE, then rgl will use the FreeType
anti-aliased fonts for drawing. This is generally desirable, and it is the
default if rgl was built to support FreeType.
FreeType fonts are specified using the rglFonts function. This function
takes a vector of four filenames of TrueType font files which
will be used for the four styles regular, bold, italic and bold italic. The
vector is passed with a name to be used as the family name, e.g.
rglFonts(sans = c("/path/to/FreeSans.ttf", ...)). In order to
limit the file size, rgl ships with just 3 font files, for
regular versions of the serif, sans and mono families.
Additional free font files are available from the Amaya project at
https://dev.w3.org/cvsweb/Amaya/fonts/. See the example below for
how to specify a full set of fonts.
Full pathnames should normally be used to specify font files. If relative paths are used, they are interpreted differently by platform. Currently Windows fonts are looked for in the Windows fonts folder, while other platforms use the current working directory.
If FreeType fonts are not used, then bitmapped fonts will be used instead.
On Windows these will be based on the fonts specified using the
windowsFonts
The adj parameter determines the position of the text relative to the
specified coordinate. Use adj = c(0, 0) to place the left bottom corner at
(x, y, z), adj = c(0.5, 0.5) to center the text there, and adj = c(1, 1)
to put the right top corner there. The optional second coordinate for vertical
adjustment defaults to 0.5. Placement is done using the "advance" of
the string and the "ascent" of the font relative to the baseline, when these metrics
are known.
text3d and texts3d draw text using the r3d
conventions. These are synonyms; the former is singular to be
consistent with the classic 2-D graphics functions, and the latter is
plural to be consistent with all the other graphics primitives. Take
your choice!
If any coordinate or text is NA, that text is not plotted.
If usePlotmath is TRUE, the work will be done
by the plotmath3d function instead of rgl.texts. This is the default if the texts
parameter is “language”, e.g. the result of
a call to expression or quote.
# NOT RUN {
open3d()
famnum <- rep(1:4, 8)
family <- c("serif", "sans", "mono", "symbol")[famnum]
font <- rep(rep(1:4, each = 4), 2)
cex <- rep(1:2, each = 16)
text3d(font, cex, famnum, text = paste(family, font), adj = 0.5,
color = "blue", family = family, font = font, cex = cex)
# }
# NOT RUN {
# These FreeType fonts are available from the Amaya project, and are not shipped
# with rgl. You would normally install them to the rgl/fonts directory
# and use fully qualified pathnames, e.g.
# system.file("fonts/FreeSerif.ttf", package = "rgl")
rglFonts(serif = c("FreeSerif.ttf", "FreeSerifBold.ttf", "FreeSerifItalic.ttf",
"FreeSerifBoldItalic.ttf"),
sans = c("FreeSans.ttf", "FreeSansBold.ttf", "FreeSansOblique.ttf",
"FreeSansBoldOblique.ttf"),
mono = c("FreeMono.ttf", "FreeMonoBold.ttf", "FreeMonoOblique.ttf",
"FreeMonoBoldOblique.ttf"),
symbol= c("ESSTIX10.TTF", "ESSTIX12.TTF", "ESSTIX9_.TTF",
"ESSTIX11.TTF"))
# }
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