csg_sphere(x = 0, y = 0, z = 0, radius = 1)

#Generate a simple sphere:
generate_ground() %>% 
  add_object(csg_object(csg_sphere(),
                        material=glossy(color="purple"))) %>% 
  render_scene(clamp_value=10)

#Generate a bigger sphere in the cornell box.
generate_cornell() %>% 
  add_object(csg_object(csg_sphere(x=555/2,y=555/2,z=555/2,radius=100),
                        material=glossy(checkercolor="purple", checkerperiod=100))) %>% 
  render_scene(clamp_value=10)
  
#Combine two spheres of different sizes
generate_cornell() %>% 
  add_object(csg_object(
    csg_combine(
      csg_sphere(x=555/2,y=555/2-50,z=555/2,radius=100),
      csg_sphere(x=555/2,y=555/2+50,z=555/2,radius=80)),
    material=glossy(color="purple"))) %>% 
  render_scene(clamp_value=10)

#Subtract two spheres to create an indented region
generate_cornell() %>% 
  add_object(csg_object(
    csg_combine(
      csg_sphere(x=555/2,y=555/2-50,z=555/2,radius=100),
      csg_sphere(x=555/2+30,y=555/2+20,z=555/2-90,radius=40),
      operation="subtract"),
    material=glossy(color="grey20"))) %>% 
  render_scene(clamp_value=10)
  
#Use csg_combine(operation="blend") to melt the two together
generate_cornell() %>% 
  add_object(csg_object(
    csg_combine(
      csg_sphere(x=555/2,y=555/2-50,z=555/2,radius=100),
      csg_sphere(x=555/2,y=555/2+50,z=555/2,radius=80),
      operation="blend", radius=20),
    material=glossy(color="purple"))) %>% 
  render_scene(clamp_value=10)