R: Generate Line Overlay

generate_line_overlay {rayshader}

R Documentation

Generate Line Overlay

Description

Calculates and returns an overlay of contour lines for the current height map.

Usage

generate_line_overlay(
  geometry,
  extent,
  heightmap = NULL,
  width = NA,
  height = NA,
  color = "black",
  linewidth = 1,
  data_column_width = NULL
)

Arguments

`geometry`	An 'sf' object with LINESTRING geometry.
`extent`	A 'raster::Extent' object with the bounding box for the height map used to generate the original map.
`heightmap`	Default 'NULL'. The original height map. Pass this in to extract the dimensions of the resulting overlay automatically.
`width`	Default 'NA'. Width of the resulting overlay. Default the same dimensions as height map.
`height`	Default 'NA'. Width of the resulting overlay. Default the same dimensions as height map.
`color`	Default 'black'. Color of the lines.
`linewidth`	Default '1'. Line width.
`data_column_width`	Default 'NULL'. The numeric column to map the width to. The maximum width will be the value specified in 'linewidth'.

Value

Semi-transparent overlay with contours.

Examples

#Add the included `sf` object with roads to the montereybay dataset

water_palette = colorRampPalette(c("darkblue", "dodgerblue", "lightblue"))(200)
bathy_hs = height_shade(montereybay, texture = water_palette)
montereybay %>% 
 height_shade() %>%
 add_overlay(generate_altitude_overlay(bathy_hs, montereybay, 0, 0))  %>%
 add_overlay(generate_line_overlay(monterey_roads_sf, 
                                   attr(montereybay,"extent"), heightmap = montereybay))  %>%
 add_shadow(ray_shade(montereybay,zscale=50),0.3) %>%
 plot_map()
 
#Change the line width, color, and transparency
montereybay %>%
 height_shade() %>%
 add_overlay(generate_altitude_overlay(bathy_hs, montereybay, 0, 0))  %>%
 add_overlay(generate_line_overlay(monterey_roads_sf, linewidth=3, color="white",
                                   attr(montereybay,"extent"), heightmap = montereybay),
                                   alphalayer=0.8)  %>%
 add_shadow(ray_shade(montereybay,zscale=50),0.3) %>%
 plot_map()
 
#Manually specify the width and height to improve visual quality of the lines
montereybay %>%
 height_shade() %>%
 add_overlay(generate_altitude_overlay(bathy_hs, montereybay, 0, 0))  %>%
 add_shadow(ray_shade(montereybay,zscale=50),0.3) %>%
 add_overlay(generate_line_overlay(monterey_roads_sf, linewidth=3, color="white",
                                   attr(montereybay,"extent"), width = 1080, height = 1080),
                                   alphalayer=0.8)  %>%
 plot_map()

[Package rayshader version 0.19.2 Index]