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Compute camera-facing direction for 3D text

Source: R/geom-text-3d.R
camera_facing.Rd

Creates a specification for camera-facing "billboard" text that will compute the appropriate facing direction for each label position.

Usage

camera_facing(
  coord = NULL,
  pitch = 0,
  roll = -60,
  yaw = -30,
  dist = 2,
  mode = c("plane", "point")
)

Arguments

pitch, roll, yaw

Rotation angles in degrees, matching the values you'll use in coord_3d().

dist

Distance from viewer to center of the data cube, matching the value you'll use in coord_3d(). Default is 2. Only used when mode = "point".

mode

Character string specifying how labels should face the camera:

  • "plane" (default): All labels face parallel to the view plane, like billboards. This is typically easier to read.

  • "point": Each label faces toward the camera position. Labels at the edges will angle inward, giving perspective-correct orientation.

Value

A camera_facing_spec object to pass to the facing parameter of geom_text_3d().

Details

With mode = "plane", all text labels face the same direction (parallel to the viewing plane), similar to traditional billboard rendering. This produces clean, readable labels.

With mode = "point", each label faces directly toward the camera's position in 3D space. Labels near the edges of the plot will angle inward, which is geometrically correct but can look less clean.

Since geom_text_3d() computes vertex positions before the view is known, you must specify the view parameters here and use the same values in coord_3d().

See also

geom_text_3d() for rendering 3D text labels

Examples

if (FALSE) { # \dontrun{
# Parallel billboard text (default) - all labels face same direction
ggplot(df, aes(x, y, z = z, label = label)) +
  geom_text_3d(facing = camera_facing(pitch = 20, roll = -60, yaw = -30)) +
  coord_3d(pitch = 20, roll = -60, yaw = -30)

# Point-facing text - labels angle toward camera position
ggplot(df, aes(x, y, z = z, label = label)) +
  geom_text_3d(facing = camera_facing(pitch = 20, roll = -60, yaw = -30,
                                      mode = "point")) +
  coord_3d(pitch = 20, roll = -60, yaw = -30)
} # }