Had a bit of time to spare. Should have cleaned up my room or done
laundry, instead I made a simple study on (scale -1) and using the
combination of colours that go over 1 and lighting to get colour
ranges as the number gets clipped for brighter sections. Well, it does
on my video-card, not sure that is defined behaviour :-)
This last bit becomes more clear by switching the relevant line to
(colour (vector 2 0 1)). I believe that for perfectly lit sections
this get clamped to (vector 1 0 1) and for half-lit sections it would
become (vector 1 0 .5), which is clearly not just more dim but also
more red. I seem to remember Gabor commenting on colours working in a
slightly different way, leading me to suspect that the results of this
depends on your card.
Copy/remix/extend/destroy/use as you see fit.
Yours,
Kas.
(clear)
(define rot (vector 0 0 0))
(define block
(let ((b (build-cube)))
(with-primitive b (recalc-normals 1))
b))
(define (ani)
(set! rot (vadd rot (vmul (vector 30 35 40) (delta))))
(let* ((P1 (vmul (vector
(* (sin (* (time) 3)))
(* (sin (* (time) 4)))
(* (sin (* (time) 5)))) 2))
(P2 (vector (vector-ref P1 1) (vector-ref P1 2) (vector-ref P1
0))))
(with-state
(colour (vector (+ 1 (cos (time))) 0 1))
(rotate rot)
(for* ((x (in-range -3 4)) (y (in-range -3 4))(z (in-range -3 4)))
(when
(<
(vdist (vector x y z) P1)
(+ 1 (abs (* 3 (sin (time))))))
(with-state
(translate (vector x y z))
(scale (if (< 1.5 (vdist (vector x y z) P2)) -1 1))
(hint-wire) (wire-colour 0) (line-width 2)
(draw-instance block)))))))
(every-frame
(ani))
Very nice effect! There is some glitchs with too close faces. Apart from
that, it render beautyful.
