Cloud Shade — cloud_shade • rayshader

Render shadows from the 3D floating cloud layer on the ground. Use this function to add shadows to the map with the add_shadow() function.

For realistic results, argument should match those passed to render_clouds(). The exception to this is attenuation_coef, which can be used to adjust the darkness of the resulting shadows.

cloud_shade(
  heightmap,
  start_altitude = 1000,
  end_altitude = 2000,
  sun_altitude = 90,
  sun_angle = 315,
  time = 0,
  cloud_cover = 0.5,
  layers = 10,
  offset_x = 0,
  offset_y = 0,
  scale_x = 1,
  scale_y = 1,
  scale_z = 1,
  frequency = 0.005,
  fractal_levels = 16,
  attenuation_coef = 1,
  seed = 1,
  zscale = 1
)

Arguments

heightmap: A two-dimensional matrix, where each entry in the matrix is the elevation at that point. This is used by render_clouds() to calculate the regions the clouds should be rendered in.
start_altitude: Default 1000. The bottom of the cloud layer.
end_altitude: Default 2000. The top of the cloud layer.
sun_altitude: Default 10. The angle, in degrees (as measured from the horizon) from which the light originates.
sun_angle: Default 315 (NW). The angle, in degrees, around the matrix from which the light originates. Zero degrees is North, increasing clockwise
time: Default 0. Advance this to make the clouds evolve and change in shape.
cloud_cover: Default 0.5. The percentage of cloud cover.
layers: Default 90. The number of layers to render the cloud layer.
offset_x: Default 0. Change this to move the cloud layer sideways.
offset_y: Default 0. Change this to move the cloud layer backwards and forward
scale_x: Default 1. Scale the fractal pattern in the x direction.
scale_y: Default 1. Scale the fractal pattern in the y direction.
scale_z: Default 1. Scale the fractal pattern in the z (altitude) direction. (automatically calculated). Scale the fractal pattern in the z (vertical) direction. s.
frequency: Default 0.005. The base frequency of the noise used to calculate the fractal cloud structure.
fractal_levels: Default 16. The fractal dimension used to calculate the noise. Higher values give more fine structure, but take longer to calculate.
attenuation_coef: Default 1. Amount of attenuation in the cloud (higher numbers give darker shadows). This value is automatically scaled to account for increasing the number of layers.
seed: Default 1. Random seed used to generate clouds.
zscale: Default 1. The ratio between the x and y spacing (which are assumed to be equal) and the z axis. For example, if the elevation levels are in units of 1 meter and the grid values are separated by 10 meters, zscale would be 10.

Value

A 2D shadow matrix.

Examples

if(run_documentation()) {
#Render clouds with cloud shadows on the ground
montereybay  %>%
 sphere_shade()  %>%
 add_shadow(cloud_shade(montereybay,zscale=50), 0.0) %>%
 plot_3d(montereybay,background="darkred",zscale=50)
render_camera(theta=-65, phi = 25, zoom = 0.45, fov = 80)
render_clouds(montereybay, zscale=50)    
render_snapshot()
}

if(run_documentation()) {
#Adjust the light direction for shadows and increase the attenuation for darker clouds
montereybay  %>%
 sphere_shade()  %>%
 add_shadow(cloud_shade(montereybay,zscale=50, sun_altitude=20, attenuation_coef = 3), 0.0) %>%
 plot_3d(montereybay,background="darkred",zscale=50)
render_camera(theta=-65, phi = 25, zoom = 0.45, fov = 80)
render_clouds(montereybay, zscale=50)    
render_snapshot()
}