Render Floating overlay

Render a 2D floating overlay over the map.

Note: Multiple layers with transparency can cause rendering issues in rgl.

render_floating_overlay(
  overlay = NULL,
  altitude = NULL,
  heightmap = NULL,
  zscale = 1,
  alpha = 1,
  baseshape = "rectangle",
  remove_na = TRUE,
  reorient = TRUE,
  clear_layers = FALSE,
  horizontal_offset = c(0, 0),
  ...
)

Arguments

overlay

Overlay (4D RGBA array) to be rendered on the 3D map.

altitude

Altitude to place the overlay.

heightmap

The underlying surface. A two-dimensional matrix, where each entry in the matrix is the elevation at that point.

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 of 1 meter and the grid values are separated by 10 meters, `zscale` would be 10. Adjust the zscale down to exaggerate elevation features.

alpha

Default `1`. Multiplies the layer's transparency by this factor. 0 is completely transparent.

baseshape

Default `rectangle`. Shape of the overlay. Options are `c("rectangle", "circle", "hex")`.

remove_na

Default `TRUE`. Whether to make the overlay transparent above empty spaces (represented by `NA` values) in the underlying elevation matrix.

reorient

Default `TRUE`. Whether to reorient the image array to match the 3D plot.

clear_layers

Default `FALSE`. Clears all existing floating layers on the visualization.

horizontal_offset

Default `c(0,0)`. Distance (in 3D space) to offset the floating offset in the x/y directions.

...

Additional arguments to pass to `rgl::triangles3d()`.

Value

Adds a 3D floating layer to the map. No return value.

Examples

if(run_documentation()) {
#Render the road network as a floating overlay layer, along with a label annotation and a floating
#point annotation
if(all(length(find.package("sf", quiet = TRUE)) > 0,
      length(find.package("magick", quiet = TRUE)) > 0)) {
 monterey = c(-121.892933,36.603053)
 monterey_city = sf::st_sfc(sf::st_point(monterey))
 
 #Generate Overlays
 road_overlay = generate_line_overlay(monterey_roads_sf, attr(montereybay,"extent"), 
                                      heightmap = montereybay)
 point_overlay = generate_point_overlay(monterey_city, color="red", size=12,
                                        attr(montereybay,"extent"), heightmap = montereybay)
                                        
 #Create 3D plot (water transparency set to 1 because multiple transparency layers can interfere)
 montereybay |>
   height_shade() |>
   add_shadow(ray_shade(montereybay,zscale=50),0.3) |> 
   plot_3d(montereybay, water = T, wateralpha = 1, windowsize = 800, watercolor = "lightblue")
 render_camera(theta=-55,phi=45,zoom=0.8)
 
 #Render label
 render_label(montereybay, lat = monterey[2], long = monterey[1], altitude = 9900,
              extent = attr(montereybay, "extent"),
              zscale = 50, text = "Monterey", textcolor = "black", linecolor="darkred")
 
 #Render Floating Overlays
 render_floating_overlay(road_overlay, altitude = 10000,zscale = 50)
 render_floating_overlay(point_overlay, altitude = 100,zscale = 50)
 render_snapshot()
}
}
#> `montereybay` dataset used with no zscale--setting `zscale=50`.  For a realistic depiction, raise `zscale` to 200.