Example how to render pointclouds in R with rayrender

render_pointcloud.R

##___________________________________________________
##
## Script name: render_pointcloud.R
##
## Purpose of script:
## render forest plot pointcloud with raytracing
##
## Author: Jens Wiesehahn
## Copyright (c) Jens Wiesehahn, 2023
## Email: [email protected]
##
## Date Created: 2023-09-10
##
## Notes:
## quite computationally intensive on large/dense datasets
##
##___________________________________________________


library(lidR)
library(rayshader)
library(here)


f <- system.file("extdata", "Megaplot.laz", package="lidR")
las <- readLAS(f)

nlas <- normalize_height(las, knnidw())
noground <- filter_poi(nlas, Classification != 2, Z >0.1)
noground <- unnormalize_height(noground)


# create DTM
dtm <- rasterize_terrain(las, 0.25, tin(), pkg = "raster")


# init 3D plot with DTM
elmat <- raster_to_matrix(dtm)
elmat %>%
  sphere_shade(zscale = 0.25, 
               texture=create_texture("white","green","white","white","white")
  ) %>%
  add_shadow(ray_shade(elmat), 0.6) %>%
  plot_3d(elmat, zscale = 0.25, fov = 45, theta = 1, zoom = 0.6, phi = 89, windowsize = c(500, 500), solid=F) 

# add vegetation points
render_points(extent = attr(dtm,"extent"),
              lat = noground@data$Y,
              long = noground@data$X,
              altitude = noground@data$Z,
              zscale=0.25,
              offset = 0,
              color=viridis::plasma(length(noground@data$Z))[rank(noground@data$Z)],
              size = 3)

# get environment light scene
download.file("https://dl.polyhaven.org/file/ph-assets/HDRIs/hdr/2k/kiara_1_dawn_2k.hdr", here("kiara_1_dawn_2k.hdr"))


# render scene
render_highquality(point_radius = 3,
                   parallel = TRUE,
                   light = FALSE,
                   environment_light = here("kiara_1_dawn_2k.hdr"),
                   clear = TRUE,
                   width = 1000,
                   height = 1000,
                   filename = here("raytraced_pointcloud.png")
                   )

Hey Jens,
Much appreciate you sharing this code example!
However, when following your example, I run into the following issue when executing render_highquality:

Error in rayvertex::validate_mesh(mesh) : 
  !any(is.na(normals)) is not TRUE

I get the same error when testing it with my data.
Any ideas?

UPDATE:
My current suspicion is that it is caused by NA values in the DTM. Potential fix:

library(imputeTS)
dtm_interpolated <- na.interpolation(dtm, option = "linear")

It works for me, so I guess its your data, otherwise you might open an issue at https://github.com/tylermorganwall/rayrender