R/render_multipolygonz.R

In rayshader: Create Maps and Visualize Data in 2D and 3D

#'@title 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
#'
#'@param sfobj An sf object with MULTIPOLYGON Z geometry.
#'@param 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. 
#'@param 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.
#'@param 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).
#'@param 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.
#'@param 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.
#'@param color Default `black`. Color of the 3D model, if `load_material = FALSE`.
#'@param offset Default `5`. Offset of the track from the surface, if `altitude = NULL`.
#'@param clear_previous Default `FALSE`. If `TRUE`, it will clear all existing points.
#'@param rgl_tag Default `""`. Tag to add to the rgl scene id, will be prefixed by `"obj"`
#'@param baseshape Default `rectangle`. Shape of the base. Options are `c("rectangle","circle","hex")`.
#'@param ... Additional arguments to pass to `rgl::triangles3d()`.
#'@export
#'@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)
#'}
render_multipolygonz = function(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",
                                ...) {
  if(clear_previous) {
    rgl::pop3d(tag = sprintf("obj%s", rgl_tag))
    if(missing(sfobj)) {
      return(invisible())
    }
  }
  obj_temp = tempfile(fileext = ".obj")
  save_multipolygonz_to_obj(sfobj, obj_temp)
  render_obj(filename = obj_temp, 
             extent = extent, obj_zscale = obj_zscale,
             clear_previous = FALSE, zscale = zscale,
             color = color, offset = offset, swap_yz = swap_yz,
             heightmap = heightmap, baseshape = baseshape, rgl_tag = rgl_tag, ...)
}