3D pillars from grid data

Creates 3D pillars from regular grid data in which x and y fall on a regular grid. Works with both complete and sparse grid data. Each data point becomes a rectangular 3D column extending from a base level to the data value.

Usage

geom_pillar_3d(
  mapping = NULL,
  data = NULL,
  stat = StatPillar3D,
  position = "identity",
  ...,
  width = 1,
  faces = "all",
  zmin = NULL,
  light = NULL,
  cull_backfaces = TRUE,
  sort_method = NULL,
  scale_depth = TRUE,
  force_convex = FALSE,
  na.rm = FALSE,
  show.legend = NA,
  inherit.aes = TRUE
)

stat_pillar_3d(
  mapping = NULL,
  data = NULL,
  geom = GeomPolygon3D,
  position = "identity",
  ...,
  width = 1,
  faces = "all",
  zmin = NULL,
  light = NULL,
  cull_backfaces = TRUE,
  sort_method = NULL,
  scale_depth = TRUE,
  force_convex = FALSE,
  na.rm = FALSE,
  show.legend = NA,
  inherit.aes = TRUE
)

Arguments

mapping

Set of aesthetic mappings created by aes().

data

The data to be displayed in this layer.

stat

The statistical transformation to use on the data. Defaults to StatPillar3D.

position

Position adjustment, defaults to "identity". To collapse the result onto one 2D surface, use position_on_face().

...

Other arguments passed on to the the layer function (typically GeomPolygon3D), such as aesthetics like colour, fill, linewidth, etc.

width

Numeric value controlling box width as a fraction of grid spacing. Default is 1.0 (volumes touch each other). Use 0.8 for small gaps, 1.2 for overlap. Grid spacing is determined automatically using resolution().

faces

Character vector specifying which faces to render. Options:

• "all" (default): Render all 6 faces

• "none": Render no faces

• Vector of face names: c("zmax", "xmin", "ymax"), etc.

Valid face names: "xmin", "xmax", "ymin", "ymax", "zmin", "zmax". Note that this setting acts jointly with backface culling, which removes faces whose interior faces the viewer – e.g., when cull_backfaces = TRUE and faces = "all" (the default), only front faces are rendered.

zmin

Base level for all pillars. When provided as a parameter, overrides any zmin aesthetic mapping. If NULL (default), uses the zmin aesthetic if mapped, otherwise defaults to the minimum z value in the data.

light

A lighting specification object created by light() (see that function for details), or NULL to disable shading. Specify plot-level lighting in coord_3d() and layer-specific lighting in geom_*3d() functions.

cull_backfaces, sort_method, force_convex, scale_depth

Advanced polygon rendering parameters. See polygon_rendering for details.

na.rm

If FALSE, missing values are removed.

show.legend

Logical indicating whether this layer should be included in legends.

inherit.aes

If FALSE, overrides the default aesthetics.

geom

The geometric object used to display the data. Defaults to GeomPolygon3D.

Value

A Layer object that can be added to a ggplot.

Details

Note that pillar geometries often require pairwise depth sorting for correct rendering. This is the default for smaller data sets, but not for larger data sets due to compute speed; in those cases you may wish to manually specify sort_method = "pairwise" for good results.

Aesthetics

stat_pillar_3d() requires the following aesthetics:

• x: X coordinate (grid position)

• y: Y coordinate (grid position)

• z: Z coordinate (pillar top height)

And optionally understands:

• zmin: Base level for each pillar (can be overridden by the zmin parameter)

Computed variables

• normal_x, normal_y, normal_z: Face normal components

• pillar_id: Sequential pillar number

• face_type: Face name ("zmax", "xmin", etc.)

See also

stat_surface_3d() for smooth surface rendering, coord_3d() for 3D coordinate systems, light() for lighting specifications, GeomPolygon3D for the default geometry.

Examples

# Basic 3D bar chart from regular grid
d <- expand.grid(x = 1:5, y = 1:5)
d$z <- d$x + d$y + rnorm(25, 0, 0.5)
ggplot(d, aes(x, y, z)) +
  geom_pillar_3d() +
  coord_3d()


# Set uniform base level using `zmin` parameter
ggplot(d, aes(x, y, z)) +
  geom_pillar_3d(aes(fill = z), color = "white",
                zmin = 0) +
  coord_3d(roll = 90)


# Set variable base levels using `zmin` aesthetic
d$base_level <- runif(nrow(d), -1, 1)
ggplot(d, aes(x, y, z = z, zmin = base_level)) +
  geom_pillar_3d(color = "black") +
  coord_3d(roll = 90)


# Show only a subset of pillar faces
ggplot(d, aes(x, y, z)) +
  geom_pillar_3d(faces = c("zmax", "ymin"),
    cull_backfaces = FALSE,
    fill = "steelblue", color = "black") +
  coord_3d()


# With gaps between pillars
ggplot(d, aes(x, y, z)) +
  geom_pillar_3d(color = "black", width = 0.6) +
  coord_3d()