In statnmap/mesh2ray: Transform mesh3d to ray* objects

knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>"
)

# Create simple mesh
simple_mesh <- Rvcg::vcgIcosahedron()

# _plot3d
plot3d(simple_mesh, col = "cyan")
aspect3d("iso")
plot3d(simple_mesh, type = "wire", add = TRUE)
plot3d(t(simple_mesh$vb), type = "s", radius = 0.1, add = TRUE)
view3d(theta = 0, phi = 10, zoom = 0.6, fov = 80)
# _snapshot
rgl.snapshot(filename = file.path(extraWD, "rayrender-simple-1-mesh.png"))
rgl::rgl.close()

# 1. Uniformely resample mesh
# _vcgUniformRemesh is included in mesh_to_cubes()
simple_resample <- vcgUniformRemesh(simple_mesh, voxelSize = 0.5, multiSample = TRUE,
                                discretize = TRUE)

plot3d(simple_resample, col = "cyan")
aspect3d("iso")
plot3d(simple_resample, type = "wire", add = TRUE)
plot3d(t(simple_resample$vb), type = "s", radius = 0.1, add = TRUE)
view3d(theta = 0, phi = 10, zoom = 0.6, fov = 80)
# _snapshot
rgl.snapshot(filename = file.path(extraWD, "rayrender-simple-2-regularmesh.png"))
rgl::rgl.close()

# 2. Calculate cube positions in a specific scene
# _vcgUniformRemesh is included in mesh_to_cubes()
simple_cubes <- mesh2ray::mesh_to_cubes(simple_mesh, voxelSize = 0.5, scene_dim = c(80, 475))

# 3. Draw with rayrender
# _scene
scene <- generate_cornell(lightintensity = 10)
# _add cubes on scene
scene <- mesh2ray::add_cubes_to_scene(scene, cubes = simple_cubes, 
                                      material = dielectric(color = "green"))
# _draw scene /!\ long calculation /!\
if (!file.exists(file.path(extraWD, "rayrender-simple-3-scene.png"))) {
  options(cores = 4)
  render_scene(scene, lookfrom = c(278, 278, -800) ,
               lookat = c(278, 278, 0), fov = 40, ambient_light = FALSE,
               samples = 500, parallel = TRUE, clamp_value = 5,
               filename =  file.path(extraWD, "rayrender-simple-3-scene.png"))
}