ggrgl extends ggplot2 into the third dimension

ggrgl

ggrgl extends ggplot2 into the third dimension.

ggrgl does this by adding a new z aesthetic which is respected when a plot is rendered to the {devoutrgl} device which renders to OpenGL via {rgl}.

Because {devoutrgl} is an interactive device, the view of the plot may be manipulated by the user - zoom, rotate, change field-of-view etc.

Slideshow

Note: interactive 3d plots cannot be displayed in a github README
file, and static images or animated gifs are used here instead.

Visit the pkgdown online
documentation to view
plots which can be manipulated in the browser.

Installation

A lot of support packages are needed for ggrgl - most of which should
already be installed if you have ggplot.

Custom packages which are needed (and not currently on CRAN):

• devout - The core
  package for writing graphics devices using R (rather than C).
• devoutrgl - a
  graphics device which renders to {rgl}
• triangular -
  decompaose polygons into triangles for 3d rendering. Much faster
  than rgl::triangulate()
• snowcrash - a package
  for encoding objects as images - needed to circumvent limitations in
  the device system provided by R
• cryogenic - a package
  for capturing a call to be evaluated later. Calls to generate 3d
  geometry are generated when plot object is created, but not executed
  until later when the plot is actually rendered to screen.

You can install from GitHub
with:

# install.package('remotes')
remotes::install_github('coolbutuseless/devout')
remotes::install_github('coolbutuseless/devoutrgl')
remotes::install_github('coolbutuseless/triangular')
remotes::install_github('coolbutuseless/snowcrash')
remotes::install_github('coolbutuseless/cryogenic')
remotes::install_github('coolbutuseless/ggrgl', ref='main')

New z Aesthetic

The new z aesthetic works the same as the x and y aesthetics in
ggplot2.

z may be mapped to a data variable or set to a constant.

New Extrusion Aesthetics

When graphical elements have a z value they are raised above the
ground.

By setting extrude = TRUE (on geoms which support it), then the raised
element is connected to the ground as if it were extruded from it.

New aesthetics control the appearance of the extruded faces and edges:

3-dimensional Geometry Types: z and 3d

ggrgl defines 2 classes of geoms: z and 3d

• z geoms are identical to their ggplot2 counterparts, except the
  entire shape may be raised (as a unit) in the z direction. The
  resulting geometry will still be planar, and parallel to the
  original plotting surface.
• 3d geoms allow for full specification of (x, y, z) locations.
  Their orientation is not constrained to be planar, or parallel to
  the original plotting surface.

Click on a geom in the following table to view its vignette

Vignettes

There are vignettes on all the new geoms in this package, see links in
the table above or click on an image below

Some vignettes with some details of the implementation and usage are:

• Technical
  Overview
  gives some details on how the 3d geometry is communicated internally
• Z
  Scaling
  shows examples how the scaling of the Z coordinate may be
  controlled.
• Keep 2d
  ‘shadows’
  demonstrates how the 2d shadow of 3d geometry may be kept for some
  supported geoms.

To see all vignettes see the online
documentation

Example - A Basic 3d Bar Plot with geom_bar_z()

#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Use `geom_bar_z` and set `z` to 200 and use extrusion
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
p <- ggplot(mpg) +
  geom_bar_z(aes(x=class, fill=class), colour='black', z=200, extrude=TRUE)


#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Render Plot in 3d with {devoutrgl}
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
devoutrgl::rgldev()
p
invisible(dev.off())

Related Software

• ggplot2 - a grammar of graphics
  implementation for 2d plots in R. ggrgl would be impossible
  without ggplot2 to build upon.

Acknowledgements

• Hadley Wickham, Thomas Lin Pedersen and others for developing and
  maintaining ggplot2
• Michael Sumner + Tyler Morgan-Wall on twitter for their in-depth
  technical advice on graphics and 3d in R
• R Core for developing and maintaining the language.
• CRAN maintainers, for patiently shepherding packages onto CRAN and
  maintaining the repository

GitHub