scatter dem

[mdsumner]

This is fun, mesh a set of points in xy and plot in rgl or as 2D, options:

• control max area a, and othe rproperties of RTriangle::triangulate eg. D for Delaunay criterion
• if z is included any Steiner points are automatically interpolated

scatter_dem <- function(x, y = NULL, z = NULL, ...) {
  x <- xy.coords(x, y)
  x <- cbind(x$x, x$y)
  PA <- NA
  if (!is.null(z)) {
    PA <- matrix(z, nrow = nrow(x))
  }
  
  p <- RTriangle::pslg(x, PA = PA)
  anglr::as.mesh3d(RTriangle::triangulate(p, ...))
}
library(raster)
library(rgl)
n <- 5000
r <- quadmesh::etopo

x <- cbind(runif(n, -180, 180), 
           runif(n, -90, 90))
x <- raster::xyFromCell(r, sample(1:ncell(r), n))
clear3d()
mesh_plot(
  dem <- scatter_dem(x, z = raster::extract(r, x), a = .5, D = TRUE)
       )
plot3d(dem)
auto_3d(z = 30)

[mdsumner]

This should go into guerrilla