Construct Displacement Sphere

displacement_sphere(
  displacement_texture,
  displacement_scale = 1,
  use_cube = FALSE,
  cube_subdivision_levels = NA,
  displace = TRUE,
  verbose = TRUE,
  position = c(0, 0, 0),
  scale = c(1, 1, 1),
  angle = c(0, 0, 0),
  pivot_point = c(0, 0, 0),
  order_rotation = c(1, 2, 3),
  material = material_list()
)

Arguments

displacement_texture: Image or matrix/array that will be used to displace the sphere.
displacement_scale: Default 1. Scale of the displacement.
use_cube: Default FALSE. Whether to use a subdivided cube instead of a UV sphere. Use this if you want to visualize areas near the poles.
cube_subdivision_levels: Default NA. Number of times to subdivide the cube before projecting it to a sphere. When NA, this is calculated from the displacement texture resolution as max(1, ceiling(log((width * height) / 12) / log(4))), where width * height is the number of pixels in the texture, 12 is the number of starting cube triangles, and each subdivision level increases the triangle count by about 4.
displace: Default TRUE. Whether to displace the sphere, or just generate the initial mesh for later displacement.
verbose: Default TRUE. Whether to print displacement texture information.
position: Default c(0,0,0). Position of the mesh.
scale: Default c(1,1,1). Scale of the mesh. Can also be a single numeric value scaling all axes uniformly.
angle: Default c(0,0,0). Angle to rotate the mesh.
pivot_point: Default c(0,0,0). Point around which to rotate the mesh.
order_rotation: Default c(1,2,3). Order to rotate the axes.
material: Default material_list() (default values). Specify the material of the object.

Value

raymesh object

Examples

texture_dim = 800
u = seq(0, 2 * pi, length.out = texture_dim)
v = seq(0, 2 * pi, length.out = texture_dim)
knit_texture = outer(u, v, function(x, y) {
  sin(10 * x + 0.75 * sin(10 * y))^2 + 0.35 * cos(12 * y)^2
})
knit_texture = (knit_texture - min(knit_texture)) / diff(range(knit_texture))
knit_texture = array(
  rep(knit_texture, 3),
  dim = c(texture_dim, texture_dim, 3)
)
rayimage::plot_image(knit_texture)

light_info = directional_light(c(1,1,1), color="dodgerblue",intensity=0.8) |>
                add_light(directional_light(c(-1,-1,0.1), color="red",intensity=0.8)) |>
                add_light(directional_light(c(0.5,1,0.5),intensity=0.8))
displacement_sphere(knit_texture,
displacement_scale = 0.08, verbose = TRUE) |>
  rasterize_scene(light_info = light_info, fov=15)
#> Displacing mesh with 800x800 texture
#> Setting `lookat` to: c(-0.00, -0.00, -0.00)


#The default sphere has issues near the poles
displacement_sphere(knit_texture, displacement_scale = 0.08) |>
  rasterize_scene(light_info = light_info, fov=10, lookfrom=c(0,10,10))
#> Displacing mesh with 800x800 texture
#> Setting `lookat` to: c(-0.00, -0.00, -0.00)


# A cube will render more nicely near the poles
displacement_sphere(knit_texture, use_cube = TRUE, displacement_scale = 0.08) |>
  rasterize_scene(light_info = light_info, fov=10, lookfrom=c(0,10,10))
#> Displacing mesh with 800x800 texture
#> Setting `lookat` to: c(-0.00, 0.00, 0.00)