hey gang
I'm trying to mess with a nurbs sphere and (eventually) distort it
using a list of values.
right now, I'm failing.... got it to work with a regular sphere
primitive, but that's a completely different beast... can someone
please help? bad code below:
;--------
(clear)
(hint-frustum-cull)
;(hint-none)
;(wire-colour #(0 1 0))
(hint-wire)
(define dims 10)
(define shape
(with-state
(build-nurbs-sphere dims dims)
)
)
(with-primitive shape
(pdata-add "n0" "v")
(pdata-copy "n" "n0")
)
(define r 1)
(define vals (build-list dims (lambda (n) (vmul (rndvec) 0.003))))
(define (bump p)
(for [(c (in-range 1 8))]
(set! r (+ 1 (remainder r dims)))
(with-primitive p
(let [(faces (/ (pdata-size) 4))]
; (printf "faces: ~s\n" faces)
(pdata-index-map! (lambda (i p n)
(let* [(face (quotient i 4))
(row (quotient face dims))
(col (remainder face dims))
(rv (list-ref vals col))]
;(printf "row: ~a\n" row)
(cond [(= face 4)
(vadd p
(vector
(* (vx rv) (vx n))
(* (vy rv) (vy n))
(* (vz rv) (vz n))
)
)
]
[else p])
)
)
"p" "n0")
)
(recalc-normals 0)
)
)
)
(every-frame (bump shape))
