RandomMaterialMarbles

From MHCGraphics

; Mead example file -- a circle of marble objects that use
; very very random materials
;
; Jim Teresco
; Computer Science 110
; Mount Holyoke College
;
; $Id: RandomMaterialMarbles.scm 601 2008-04-01 16:02:12Z terescoj $
;
(require (lib "Defs.ss" "Mead"))

; These functions add multiple objects, each with a very
; random material
(define (rand low high)
   (+ low (* (random) (- high low)))
  )

(define (veryRandomMatAdd n obj group initialXform deltaXform)
  (if (<= n 0) group
      (let* ([m (new Material)]
             )
        ; now we can give our material the properties we want
        (tell m
              ; a completely random color
              (color (list (random) (random) (random)))
              (ambient (rand 0 .4))
              (diffuse (rand .2 1))
              (roughness (rand 0 1.5))
              (specularity (rand 0 .5))
              (reflection (rand 0 .5))
              (transparency (rand 0 .5))
              (refraction (rand .75 1.6))
              )
        ; add one instance of our object to the group, but
        ; also specify our brand new material
        (tell group (add obj initialXform m))
        ; now add the other n-1 copies
        (veryRandomMatAdd (- n 1) obj group
                      (compose initialXform deltaXform)
                      deltaXform)
        )
      )
  )

; we'll use this to place a bunch of marbles in a circle
; about the y-axis

; our marble is just a 50x50x50 sphere, that by default
; sits atop the origin, no material specified yet
(object marble Sphere
        (scale .5 .5 .5)
        (translate 0 25 0)
        )

; define names for the number or marbles and how far
; around we'll need to rotate each to get a nice circle of
; marbles
(define numMarbles 24)
(define angleSpacing (/ 360 numMarbles))
(define layoutRadius 300)
  
(veryRandomMatAdd numMarbles marble scene
              ; our first marble is translated out
              ; by some amount along x
              (translate layoutRadius 0 0)
              ; subsequent marbles are each rotated around
              ; the y-axis by an appropriate amount
              (yRot angleSpacing)
              )

; put in a floor and a few lights
(object dimBulb Light
        (intensity .25)
        )
(tell scene
      (add dimBulb (translate 500 800 500))
      (add dimBulb (translate -500 800 500))
      (add dimBulb (translate 500 800 -500))
      (add dimBulb (translate -500 800 -500))
      (add (new Plane) whitePlastic))

(tell image
      (background white)
      (antiAlias 1)
      (dimensions 800 600)
      (quality 11)
      )

(tell camera
      (pos '(0 300 -600))
      (angle 60)
      (shoot))