map3d.R

## https://stackoverflow.com/questions/44197462/plotting-3d-bars-on-top-of-the-map-using-r
# Plotting 3D maps using OpenStreetMap and RGL. For info see: 
# http://geotheory.co.uk/blog/2013/04/26/plotting-3d-maps-with-rgl/
map3d <- function(map, ...){
  if(length(map$tiles)!=1){stop("multiple tiles not implemented") }
  nx = map$tiles[[1]]$xres
  ny = map$tiles[[1]]$yres
  xmin = map$tiles[[1]]$bbox$p1[1]
  xmax = map$tiles[[1]]$bbox$p2[1]
  ymin = map$tiles[[1]]$bbox$p1[2]
  ymax = map$tiles[[1]]$bbox$p2[2]
  xc = seq(xmin,xmax,len=ny)
  yc = seq(ymin,ymax,len=nx)
  colours = matrix(map$tiles[[1]]$colorData,ny,nx)
  m = matrix(0,ny,nx)
  surface3d(xc,yc,m,col=colours, ...)
  return(list(xc=xc, yc=yc, colours=colours))
}
require(rgl)
require(OpenStreetMap)
map <- openproj(openmap(c(52.5227,13.2974),c(52.4329,13.5669), zoom = 10))
set.seed(1)
n <- 30
bbox <- unlist(map$bbox, use.names = F)
x <- do.call(runif, c(list(n), as.list(bbox[c(1,3)])))
y <- do.call(runif, c(list(n), as.list(bbox[c(4,2)])))
z <- runif(n, 0, .1)
m <- rbind(cbind(x,y,z=0), cbind(x,y,z))
m <- m[as.vector(mapply(c, 1:n, (n+1):(2*n))),]
open3d(windowRect=c(100,100,800,600))
coords <- map3d(map, lit=F)
segments3d(m, col="red", add=T)