segment {rayrender}

Segment Object

Description

Similar to the cylinder object, but specified by start and end points.

Usage

segment(
  start = c(0, -1, 0),
  end = c(0, 1, 0),
  radius = 0.1,
  phi_min = 0,
  phi_max = 360,
  from_center = TRUE,
  direction = NA,
  material = diffuse(),
  capped = TRUE,
  flipped = FALSE,
  scale = c(1, 1, 1)
)

Arguments

start

Default 'c(0, -1, 0)'. Start point of the cylinder segment, specifing 'x', 'y', 'z'.

end

Default 'c(0, 1, 0)'. End point of the cylinder segment, specifing 'x', 'y', 'z'.

radius

Default '1'. Radius of the segment.

phi_min

Default '0'. Minimum angle around the segment.

phi_max

Default '360'. Maximum angle around the segment.

from_center

Default 'TRUE'. If orientation specified via 'direction', setting this argument to 'FALSE' will make 'start' specify the bottom of the segment, instead of the middle.

direction

Default 'NA'. Alternative to 'start' and 'end', specify the direction (via a length-3 vector) of the segment. Segment will be centered at 'start', and the length will be determined by the magnitude of the direction vector.

material

Default diffuse.The material, called from one of the material functions diffuse, metal, or dielectric.

capped

Default 'TRUE'. Whether to add caps to the segment. Turned off when using the 'light()' material.

flipped

Default 'FALSE'. Whether to flip the normals.

scale

Default 'c(1, 1, 1)'. Scale transformation in the x, y, and z directions. If this is a single value, number, the object will be scaled uniformly. Notes: this will change the stated start/end position of the segment. Emissive objects may not currently function correctly when scaled.

Value

Single row of a tibble describing the segment in the scene.

Examples

#Generate a segment in the cornell box. 
if(run_documentation()) {
generate_cornell() %>%
  add_object(segment(start = c(100, 100, 100), end = c(455, 455, 455), radius = 50)) %>%
  render_scene(lookfrom = c(278, 278, -800) ,lookat = c(278, 278, 0), fov = 40, 
               ambient_light = FALSE, samples = 128, parallel = TRUE, clamp_value = 5)
}

# Draw a line graph representing a normal distribution, but with metal:
xvals = seq(-3, 3, length.out = 30)
yvals = dnorm(xvals)

scene_list = list()
for(i in 1:(length(xvals) - 1)) {
  scene_list[[i]] = segment(start = c(555/2 + xvals[i] * 80, yvals[i] * 800, 555/2),
                            end = c(555/2 + xvals[i + 1] * 80, yvals[i + 1] * 800, 555/2),
                            radius = 10,
                            material = metal())
}
scene_segments = do.call(rbind,scene_list)
if(run_documentation()) {
generate_cornell() %>% 
  add_object(scene_segments) %>%
  render_scene(lookfrom = c(278, 278, -800) ,lookat = c(278, 278, 0), fov = 40, 
               ambient_light = FALSE, samples = 128, parallel = TRUE, clamp_value = 5)
}

#Draw the outline of a cube:

cube_outline = segment(start = c(100, 100, 100), end = c(100, 100, 455), radius = 10) %>%
  add_object(segment(start = c(100, 100, 100), end = c(100, 455, 100), radius = 10)) %>%
  add_object(segment(start = c(100, 100, 100), end = c(455, 100, 100), radius = 10)) %>%
  add_object(segment(start = c(100, 100, 455), end = c(100, 455, 455), radius = 10)) %>%
  add_object(segment(start = c(100, 100, 455), end = c(455, 100, 455), radius = 10)) %>%
  add_object(segment(start = c(100, 455, 455), end = c(100, 455, 100), radius = 10)) %>%
  add_object(segment(start = c(100, 455, 455), end = c(455, 455, 455), radius = 10)) %>%
  add_object(segment(start = c(455, 455, 100), end = c(455, 100, 100), radius = 10)) %>%
  add_object(segment(start = c(455, 455, 100), end = c(455, 455, 455), radius = 10)) %>%
  add_object(segment(start = c(455, 100, 100), end = c(455, 100, 455), radius = 10)) %>%
  add_object(segment(start = c(455, 100, 455), end = c(455, 455, 455), radius = 10)) %>%
  add_object(segment(start = c(100, 455, 100), end = c(455, 455, 100), radius = 10))

if(run_documentation()) {
generate_cornell() %>%
  add_object(cube_outline) %>%
  render_scene(lookfrom = c(278, 278, -800) ,lookat = c(278, 278, 0), fov = 40, 
               ambient_light = FALSE, samples = 128, parallel = TRUE, clamp_value = 5)
}

#Shrink and rotate the cube
if(run_documentation()) {
generate_cornell() %>%
  add_object(group_objects(cube_outline, pivot_point = c(555/2, 555/2, 555/2),
                           angle = c(45,45,45), scale = c(0.5,0.5,0.5))) %>%
  render_scene(lookfrom = c(278, 278, -800) ,lookat = c(278, 278, 0), fov = 40, 
               ambient_light = FALSE, samples = 128, parallel = TRUE, clamp_value = 5)
}