R: Generate sprites using base graphics math plotting.

plotmath3d {rgl} | R Documentation

## Generate sprites using base graphics math plotting.

### Description

To plot mathematical text, this function uses base graphics functions to plot it to a ‘.png’ file, then uses that file as a texture in a sprite.

### Usage

    plotmath3d(x, y = NULL, z = NULL, text, cex = par("cex"), adj = par("adj"),
               fixedSize = TRUE, startsize = 480, initCex = 5, ...)

### Arguments

`x, y, z` | coordinates. Any reasonable way of defining the coordinates is acceptable. See the function `xyz.coords` for details.
`text` | A character vector or expression. See `plotmath` for how expressions are interpreted.
`cex` | Character size expansion.
`adj` | one value specifying the horizontal adjustment, or two, specifying horizontal and vertical adjustment respectively.
`fixedSize` | Should the resulting sprite behave like the default ones, and resize with the scene, or like text, and stay at a fixed size?
`startsize, initCex` | These parameters are unlikely to be needed by users. `startsize` is an over-estimate of the size (in pixels) of the largest expression. Increase this if large expressions are cut off. `initCex` is the size of text used to form the bitmap. Increase this if letters look too blurry at the desired size.
`...` | Additional arguments to pass to `text` when drawing the text.

### Value

Called for the side effect of displaying the sprites. The shape ID of the displayed object is returned.

### Note

The `text3d` function passes calls to this function if its `usePlotmath` argument is `TRUE`. The default value is determined by examining its `texts` argument; if it looks like an expression, `plotmath3d` is used.

### Author(s)

Duncan Murdoch

### See Also

`text3d`

### Examples

    open3d()
    plotmath3d(1:3, 1:3, 1:3, expression(x[1] == 1, x[2] == 2, x[3] == 3))
    # This lets the text resize with the plot
    text3d(4, 4, 4, "resizeable text", usePlotmath = TRUE, fixedSize = FALSE)

[Package rgl version 0.99.9 Index]