Render Label — render_label • rayshader

Adds a marker and label to the current 3D plot

render_label(
  heightmap,
  text,
  lat,
  long,
  altitude = NULL,
  extent = NULL,
  x = NULL,
  y = NULL,
  z = NULL,
  zscale = 1,
  relativez = TRUE,
  offset = 0,
  clear_previous = FALSE,
  textsize = 1,
  dashed = FALSE,
  dashlength = "auto",
  linewidth = 3,
  antialias = FALSE,
  alpha = 1,
  textalpha = 1,
  freetype = TRUE,
  adjustvec = NULL,
  family = "sans",
  fonttype = "standard",
  linecolor = "black",
  textcolor = "black"
)

Arguments

heightmap: A two-dimensional matrix, where each entry in the matrix is the elevation at that point. All points are assumed to be evenly spaced.
text: The label text.
lat: A latitude for the text. Must provide an raster::extent object to argument extent for the map.
long: A latitude for the text. Must provide an raster::extent object to argument extent for the map.
altitude: Default NULL. Elevation of the label, in units of the elevation matrix (scaled by zscale). If none is passed, this will default to 10 percent above the maximum altitude in the heightmap.
extent: Either an object representing the spatial extent of the scene (either from the raster, terra, sf, or sp packages), a length-4 numeric vector specifying c("xmin", "xmax","ymin","ymax"), or the spatial object (from the previously aforementioned packages) which will be automatically converted to an extent object.
x: Default NULL. Directly specify the x index in the matrix to place the label.
y: Default NULL. Directly specify the y index in the matrix to place the label.
z: Default NULL. Elevation of the label, in units of the elevation matrix (scaled by zscale).
zscale: Default 1. The ratio between the x and y spacing (which are assumed to be equal) and the z axis. For example, if the elevation levels are in units
relativez: Default TRUE. Whether z should be measured in relation to the underlying elevation at that point in the heightmap, or set absolutely (FALSE).
offset: Elevation above the surface (at the label point) to start drawing the line.
clear_previous: Default FALSE. If TRUE, it will clear all existing text and lines rendered with render_label(). If no other arguments are passed to render_label(), this will just remove all existing lines.
textsize: Default 1. A numeric character expansion value.
dashed: Default FALSE. If TRUE, the label line is dashed.
dashlength: Default auto. Length, in units of the elevation matrix (scaled by zscale) of the dashes if dashed = TRUE.
linewidth: Default 3. The line width.
antialias: Default FALSE. If TRUE, the line with be have anti-aliasing applied. NOTE: anti-aliasing can cause some unpredictable behavior with transparent surfaces.
alpha: Default 1. Transparency of the label line.
textalpha: Default 1. Transparency of the label text.
freetype: Default TRUE. Set to FALSE if freetype is not installed (freetype enables anti-aliased fonts). NOTE: There are occasionally transparency issues when positioning Freetype fonts in front and behind a transparent surface.
adjustvec: Default c(0.5,-0.5). The horizontal and vertical offset for the text. If freetype = FALSE and on macOS/Linux, this is adjusted to c(0.33,-0.5) to keep the type centered.
family: Default "sans". Font family. Choices are c("serif", "sans", "mono", "symbol").
fonttype: Default "standard". The font type. Choices are c("standard", "bold", "italic", "bolditalic"). NOTE: These require FreeType fonts, which may not be installed on your system. See the documentation for rgl::text3d() for more information.
linecolor: Default black. Color of the line.
textcolor: Default black. Color of the text.

Examples

if(run_documentation()) {
montereybay %>%
 sphere_shade() %>%
 plot_3d(montereybay,zscale=50,water=TRUE, watercolor="#233aa1")
render_snapshot() 
}


santa_cruz = c(36.962957, -122.021033) 
#We want to add a label to Santa Cruz, so we use the x and y matrix coordinate (x=220 and y=330)
if(run_documentation()) {
render_label(montereybay,lat = santa_cruz[1], long = santa_cruz[2],
            extent = attr(montereybay, "extent"),
            altitude=12000, zscale=50, text = "Santa Cruz")
render_snapshot()
}


monterey = c(36.603053, -121.892933)
#We can also change the linetype to dashed by setting `dashed = TRUE` (additional options allow
#the user to control the dash length). You can clear the existing lines by setting 
#`clear_previous = TRUE`.
if(run_documentation()) {
render_label(montereybay, lat = monterey[1], long = monterey[2], altitude = 10000, 
            extent = attr(montereybay, "extent"),
            zscale = 50, text = "Monterey", textcolor = "white", linecolor="darkred",
            dashed = TRUE, clear_previous = TRUE)
render_snapshot()
}
#> Error in validate_mesh(scene): !any(is.na(normals)) is not TRUE

canyon = c(36.621049, -122.333912)
#By default, z specifies the altitude above that point on the elevation matrix. We can also specify 
#an absolute height by setting `relativez=FALSE`.
if(run_documentation()) {
render_label(montereybay,lat=canyon[1], long = canyon[2], altitude = 2000,
            extent = attr(montereybay,"extent"),
            zscale=50,text = "Monterey Canyon", relativez=FALSE)
render_snapshot()
}
#> Error in validate_mesh(scene): !any(is.na(normals)) is not TRUE

#We can also render labels in high quality with `render_highquality()`, specifying a custom
#line radius. By default, the labels point towards the camera, but you can fix their angle with
#argument `text_angle`.
if(run_documentation()) {
render_camera(theta=35, phi = 35, zoom = 0.80, fov=60)
render_label(montereybay, lat = monterey[1], long = monterey[2], altitude = 10000, 
            extent = attr(montereybay, "extent"),
            zscale = 50, text = "Monterey", textcolor = "white", linecolor="darkred",
            dashed = TRUE, clear_previous = TRUE)
               
render_label(montereybay,lat=canyon[1], long = canyon[2], altitude = 2000, zscale=50,
            extent = attr(montereybay,"extent"), textcolor = "white", linecolor="white",
            text = "Monterey Canyon", relativez=FALSE)
            
render_highquality(samples = 128,text_size = 24, line_radius = 2, text_offset = c(0, 20, 0),
                  lightdirection = 180, clamp_value = 10, min_variance = 0,
                  sample_method = "sobol_blue")
}

if(run_documentation()) {
#Fixed text angle
render_highquality(samples = 128,text_size = 24, line_radius = 2, text_offset = c(0, 20, 0),
                  lightdirection = 180, text_angle = 0, clamp_value=10, min_variance = 0,
                  sample_method = "sobol_blue")
}

#We can remove all existing labels by calling `render_label(clear_previous = TRUE)`
if(run_documentation()) {
render_label(clear_previous = TRUE) 
render_snapshot()
}