Bezier Curve Object — bezier

Bezier curve, defined by 4 control points.

bezier_curve(
  p1 = c(0, 0, 0),
  p2 = c(-1, 0.33, 0),
  p3 = c(1, 0.66, 0),
  p4 = c(0, 1, 0),
  x = 0,
  y = 0,
  z = 0,
  width = 0.1,
  width_end = NA,
  u_min = 0,
  u_max = 1,
  type = "cylinder",
  normal = c(0, 0, -1),
  normal_end = NA,
  material = diffuse(),
  angle = c(0, 0, 0),
  order_rotation = c(1, 2, 3),
  flipped = FALSE,
  scale = c(1, 1, 1)
)

Arguments

p1: Default `c(0,0,0)`. First control point. Can also be a list of 4 length-3 numeric vectors or 4x3 matrix/data.frame specifying the x/y/z control points.
p2: Default `c(-1,0.33,0)`. Second control point.
p3: Default `c(1,0.66,0)`. Third control point.
p4: Default `c(0,1,0)`. Fourth control point.
x: Default `0`. x-coordinate offset for the curve.
y: Default `0`. y-coordinate offset for the curve.
z: Default `0`. z-coordinate offset for the curve.
width: Default `0.1`. Curve width.
width_end: Default `NA`. Width at end of path. Same as `width`, unless specified.
u_min: Default `0`. Minimum parametric coordinate for the curve.
u_max: Default `1`. Maximum parametric coordinate for the curve.
type: Default `cylinder`. Other options are `flat` and `ribbon`.
normal: Default `c(0,0,-1)`. Orientation surface normal for the start of ribbon curves.
normal_end: Default `NA`. Orientation surface normal for the start of ribbon curves. If not specified, same as `normal`.
material: Default diffuse.The material, called from one of the material functions diffuse, metal, or dielectric.
angle: Default `c(0, 0, 0)`. Angle of rotation around the x, y, and z axes, applied in the order specified in `order_rotation`.
order_rotation: Default `c(1, 2, 3)`. The order to apply the rotations, referring to "x", "y", and "z".
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. Note: emissive objects may not currently function correctly when scaled.

Value

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

Examples

#Generate the default curve:
if(run_documentation()) {
generate_studio(depth=-0.2) %>%
  add_object(bezier_curve(material=diffuse(color="red"))) %>%
  add_object(sphere(y=3,z=5,x=2,radius=0.3,
                    material=light(intensity=200, spotlight_focus = c(0,0.5,0)))) %>%
  render_scene(clamp_value = 10, lookat = c(0,0.5,0), fov=13,
               samples=128)
}


if(run_documentation()) {
#Change the control points to change the direction of the curve. Here, we place spheres
#at the control point locations.
generate_studio(depth=-0.2) %>%
  add_object(bezier_curve(material=diffuse(color="red"))) %>%
  add_object(sphere(radius=0.075,material=glossy(color="green"))) %>% 
  add_object(sphere(radius=0.075,x=-1,y=0.33,material=glossy(color="green"))) %>% 
  add_object(sphere(radius=0.075,x=1,y=0.66,material=glossy(color="green"))) %>% 
  add_object(sphere(radius=0.075,y=1,material=glossy(color="green"))) %>% 
  add_object(sphere(y=3,z=5,x=2,radius=0.3,
                    material=light(intensity=200, spotlight_focus = c(0,0.5,0)))) %>%
  render_scene(clamp_value = 10, lookat = c(0,0.5,0), fov=15,
               samples=128)
}

if(run_documentation()) {
#We can make the curve flat (always facing the camera) by setting the type to `flat`
generate_studio(depth=-0.2) %>%
  add_object(bezier_curve(type="flat", material=glossy(color="red"))) %>%
  add_object(sphere(y=3,z=5,x=2,radius=0.3,
                    material=light(intensity=200, spotlight_focus = c(0,0.5,0)))) %>%
  render_scene(clamp_value = 10, lookat = c(0,0.5,0), fov=13,
               samples=128)
}

if(run_documentation()) {
#We can also plot a ribbon, which is further specified by a start and end orientation with
#two surface normals.
generate_studio(depth=-0.2) %>%
  add_object(bezier_curve(type="ribbon", width=0.2,
                   p1 = c(0,0,0), p2 = c(0,0.33,0), p3 = c(0,0.66,0), p4 = c(0.3,1,0),
                   normal_end = c(0,0,1),
                   material=glossy(color="red"))) %>%
  add_object(sphere(y=3,z=5,x=2,radius=0.3,
                    material=light(intensity=200, spotlight_focus = c(0,0.5,0)))) %>%
  render_scene(clamp_value = 10, lookat = c(0,0.5,0), fov=13,
               samples=128)
}

if(run_documentation()) {
#Create a single curve and copy and rotate it around the y-axis to create a wavy fountain effect:
scene_curves = list()
for(i in 1:90) {
  scene_curves[[i]] = bezier_curve(p1 = c(0,0,0),p2 = c(0,5-sinpi(i*16/180),2),
                            p3 = c(0,5-0.5 * sinpi(i*16/180),4),p4 = c(0,0,6),
                            angle=c(0,i*4,0), type="cylinder",
                            width = 0.1, width_end =0.1,material=glossy(color="red"))
}
all_curves = do.call(rbind, scene_curves)
generate_ground(depth=0,material=diffuse(checkercolor="grey20")) %>%
  add_object(all_curves) %>%
  add_object(sphere(y=7,z=0,x=0,material=light(intensity=100))) %>% 
  render_scene(lookfrom = c(12,20,50),samples=100,
               lookat=c(0,1,0), fov=15, clamp_value = 10)

}