render_multipolygonz {rayshader}

Render MULTIPOLYGON Z Geometry

Description

Adds MULTIPOLYGONZ will be plotted in the coordinate system set by the user-specified 'extent' argument as-is.

You can also use 'save_multipolygonz_to_obj()' manually to convert sf objects

Usage

render_multipolygonz(
  sfobj,
  extent = NULL,
  zscale = 1,
  heightmap = NULL,
  color = "grey50",
  offset = 0,
  obj_zscale = TRUE,
  swap_yz = TRUE,
  clear_previous = FALSE,
  baseshape = "rectangle",
  rgl_tag = "_multipolygon",
  ...
)

Arguments

sfobj

An sf object with MULTIPOLYGON Z geometry.

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.

zscale

Default '1'. The ratio between the x and y spacing (which are assumed to be equal) and the z axis in the original heightmap.

heightmap

Default 'NULL'. Automatically extracted from the rgl window–only use if auto-extraction of matrix extent isn't working. A two-dimensional matrix, where each entry in the matrix is the elevation at that point. All points are assumed to be evenly spaced.

color

Default 'black'. Color of the 3D model, if 'load_material = FALSE'.

offset

Default '5'. Offset of the track from the surface, if 'altitude = NULL'.

obj_zscale

Default 'TRUE'. Whether to scale the size of the OBJ by zscale to have it match the size of the map. If zscale is very big, this will make the model very small.

swap_yz

Default 'TRUE'. Whether to swap and Y and Z axes. (Y axis is vertical in rayshader coordinates, but data is often provided with Z being vertical).

clear_previous

Default 'FALSE'. If 'TRUE', it will clear all existing points.

baseshape

Default 'rectangle'. Shape of the base. Options are 'c("rectangle","circle","hex")'.

rgl_tag

Default '""'. Tag to add to the rgl scene id, will be prefixed by '"obj"'

...

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

Examples

run_examples = length(find.package("sf", quiet = TRUE)) &&
              length(find.package("elevatr", quiet = TRUE)) &&
              length(find.package("raster", quiet = TRUE)) &&
              run_documentation()
if(run_examples) {
library(sf)
#Set location of washington monument
washington_monument_location =  st_point(c(-77.035249, 38.889462))
wm_point = washington_monument_location |> 
 st_point() |> 
 st_sfc(crs = 4326) |> 
 st_transform(st_crs(washington_monument_multipolygonz))
 
elevation_data = elevatr::get_elev_raster(locations = wm_point, z = 14)
                                         
scene_bbox = st_bbox(st_buffer(wm_point,300))
cropped_data = raster::crop(elevation_data, scene_bbox)

#Use rayshader to convert that raster data to a matrix
dc_elevation_matrix = raster_to_matrix(cropped_data)

#Remove negative elevation data
dc_elevation_matrix[dc_elevation_matrix < 0] = 0

#Plot a 3D map of the national mall
dc_elevation_matrix |> 
 height_shade() |>
 add_shadow(lamb_shade(dc_elevation_matrix), 0) |> 
 plot_3d(dc_elevation_matrix, zscale=3.7, water = TRUE, waterdepth = 1, 
         soliddepth=-50, windowsize = 800)
render_snapshot()
}
if(run_examples) {
#Zoom in on the monument
render_camera(theta=150,  phi=35, zoom= 0.55, fov=70)
#Render the national monument
rgl::par3d(ignoreExtent = TRUE)
render_multipolygonz(washington_monument_multipolygonz, 
                    extent = raster::extent(cropped_data), 
                    zscale = 4, color = "white",
                    heightmap = dc_elevation_matrix)
render_snapshot()
}
if(run_examples) {
#This works with `render_highquality()`
render_highquality(sample_method="sobol_blue", clamp_value=10, min_variance = 0)
}