Dynamic Shader Example Code

(set! time 0)

; loop for thirty frames
(while (< time 30)
  (begin

   (world
    (camera "main" "perspective" 'from '(2.5 2 3.5) 
            'to '(0 1 0) 'fov 45)

    (light "spotlight" 'intensity 15
           'from '(0 3 2))
    (separator
     (color '(1 0 0))
     (rotate '90 '(1 0 0))
     (surface "plastic")
     (disk 'radius 20)
     )
    (translate '(0 1 0))
    (color '(.7 .5 .3))
    (surface "cmarble" 'veining (+ 12 (* 4 (/ time 29))))
    (read-det "skull.obj" "smooth")
   )

   ; set the frame name to "Frames/frame."
   ((render 'to-file) (string-append "Frames/frame." 
                                     (number->string time)))
   ; render from the point of view of the light called "main"
   (render "main")

   ; increment the value of time by one
   (set! time (+ time 1))
   )
 )