Code generated from the [[RealtimeAV Workshop]] [20060807-11]





<file>
; a experiment in using the turtle to create a 
; constantly regenerating procedural shape from 
; a static triangle strip. there are lots of 
; obvious problems with this technique, and bugs 
; in this implementation - but it's still capable 
; of some interesting things (note: to do this 
; properly fluxus needs an operation to "rotate" 
; the vertex data around in memory)

; triangle strips are laid out like this:
;
; 0___2___4___6
; |  /|  /|  /|
; | / | / | / |
; |/__|/__|/__|
; 1   3   5   7
;
; where the numbers indicate the vertex 
; positions in the list (= pdata indices)


; make a circle - skipping a vert each time, 
; so builds one side of a vertex strip. 
; this represents the cross section of the 
; shape we are building

(define (circle count radius)
    (define (loop i angle)
        (turtle-move radius)
        (turtle-turn (vector 0 angle 0))
        (turtle-vert)
        (turtle-skip 1)
        (if (zero? (- i 1))
            0
            (loop (- i 1) angle)))

    (turtle-push)
    (loop count (/ 360 count))
    (turtle-pop))

; build the next level of shape, made out of 
; the circles above - assembles it two circles 
; at a time, building the triangle strip into 
; rings - effectively extruding the circles 
; into a tube

(define (shape circlecount shapecount)   
    (circle circlecount 1)                     ; draw a circle of radius 1
    (turtle-skip (- (- (* circlecount 2) 1)))  ; skip backwards by some algorithm? :)
    (turtle-turn (vector 0 0 90))              ; turn to face the direction of the tube
    (turtle-turn (vector 5 0 0))               ; turn half of the bend amount
    (turtle-move 2)                            ; move forward
    (turtle-turn (vector 5 0 0))               ; turn the second half of the bend amount
    (turtle-turn (vector 0 0 -90))             ; face the direction to draw the circle
    (circle circlecount 1)                     ; draw the second circle
    (turtle-skip -1)                           ; set up for the next circle
    (if (zero? shapecount)
        0
        (shape circlecount (- shapecount 1))))

(clear)
(backfacecull 0)
(define o (build-polygons 500 0)) ; make an arbitary length triangle strip
(turtle-attach o)                 ; attach the turtle builder to it
(turtle-reset)

(define nexttime 0) ; adding to the strip each frame is way too fast, so
                    ; use the timer to slow down...

(define (update)
        (cond ((< nexttime (time))
            (set! nexttime (+ (time) 0.1)) ; do this every 0.1 seconds
            (grab o)        
            (shape 12 1)
            (recalc-normals 0)
            (ungrab))))

(every-frame (update))

</file>

{{http://www.pawfal.org/dave/images/retreat/Screenshot-1.jpg|Screenshot-1.jpg}}

<file>
; virualtim
;
; reads muscle data from osc and uses it to control a 
; physical arm model 

; turn on full debugging
(debug-enable 'debug)
(debug-enable 'backtrace)
(read-enable 'positions)

; makes an arm segment - a bone and a joint connecting it
; with the input attachto object - can be used for chaining 
; together objects
(define (make-arm-seg attachto axis)
    (push)
    (scale (vector 0.4 0.4 2))
    (let ((bone (build-cube)))
    (pop)
    
    (grab bone)
    (let ((jointpos (vtransform (vector 0 0 -0.5) (get-transform))))
    (ungrab)
    (active-box bone)

    (let ((joint (build-hingejoint attachto bone jointpos axis)))
   
    (joint-param joint "LoStop" -2) 
    (joint-param joint "HiStop" 2)     
    (joint-param joint "FMax" 100) 
    (joint-param joint "FudgeFactor" 0)

    (list bone joint)))))

(define (arm-seg-get-bone arm-seg)
    (list-ref arm-seg 0))

(define (arm-seg-get-joint arm-seg)
    (list-ref arm-seg 1))

(define (make-arm)

    (push)
    (translate (vector 0 1.5 0))
    (scale (vector 1 3 2))
    (let ((torso (build-cube)))
    (pop)
    
    (active-box torso)
    (build-fixedjoint torso)

    (translate (vector 0 2.6 2.2))
    (let ((upper-arm (make-arm-seg torso (vector 0 1 0))))

    (translate (vector 0 0 2.2))
    (let ((lower-arm (make-arm-seg (arm-seg-get-bone upper-arm) (vector 1 0 0))))

    (translate (vector 0 0 1.4))
    (scale (vector 1 1 0.3))
    (let ((hand (make-arm-seg (arm-seg-get-bone lower-arm) (vector 1 0 0))))

    (list upper-arm lower-arm hand))))))


(osc-source "9999")

(define (arm-update arm)
    (let ((shoulder (arm-seg-get-joint (list-ref arm 0)))
          (elbow (arm-seg-get-joint (list-ref arm 1)))
          (wrist (arm-seg-get-joint (list-ref arm 2))))

    (define (drain-upper)
        (cond
            ((osc-msg "/bodydata/1/upper")
                (display (osc 0))(newline)
                (joint-angle shoulder 1 (* (osc 0) 2))
                (drain-upper))))

    (define (drain-lower)
        (cond
            ((osc-msg "/bodydata/1/lower")
                (display (osc 0))(newline)
   
                (joint-angle elbow 1 (* (osc 0) 2))
                (drain-lower))))

;    (joint-angle shoulder 1 1)

     
    (drain-upper)
    (drain-lower)))
    


(gravity (vector 0 -0.01 0))
(show-axis 1)
(clear)
(collisions 1)

(ground-plane (vector 0 1 0) 0)
(push)
(scale (vector 10 10 10))
(rotate (vector 90 0 0))
(build-plane)
(pop)

(define arm (make-arm))

(define (update)
    (arm-update arm))

(every-frame (update)) 

</file>


{{http://www.pawfal.org/dave/images/retreat/Screenshot-2.jpg|Screenshot-2.jpg}}



<file>
; a sound and muscle controlled tube doodler
; includes texture coordinate generation, and
; automatic tracking camera

(define (circle n radius s)
    (define (loop i angle)
        (turtle-move radius)
        (turtle-turn (vector 0 angle 0))
        (turtle-vert)
        (pdata-set "t" (turtle-position) (vector (/ n i) (* s 0.1) 0))
        (turtle-skip 1)
        (if (zero? (- i 1))
            0
            (loop (- i 1) angle)))

    (turtle-push)
    (loop n (/ 360 n))
    (turtle-pop))

(define lastwidth 1)
(define turnx 0)
(define turny 0)

(define (shape c n)
    (set! turnx (gh 2))
    (set! turny (gh 3))
    (if (> turnx 90) (set! turnx 90))
    (if (> turny 90) (set! turny 90))

    (circle c lastwidth n)
    (turtle-skip (- (- (* c 2) 1)))
    (turtle-turn (vector 0 0 90))
    (turtle-turn (vmul (vector turnx turny 0) 0.1))
    (turtle-move 2)
    (turtle-turn (vmul (vector turnx turny 0) 0.1))
    (turtle-turn (vector 0 0 -90))
    (set! lastwidth (+ (* lastwidth 0.9) (* (gh 8) 0.001)))

    (circle c lastwidth (+ n 1))
    (turtle-skip -1)
    (if (zero? n)
        0
        (shape c (- n 1))))

(clear)
(backfacecull 0)
(clear-colour (vector 0 0 0))
;(hint-wire)
;(hint-unlit)
;(texture (load-texture "rhod.png"))
(define o (build-polygons 5000 0))
(turtle-attach o)
(turtle-reset)

(gain 100)

(define camera (build-locator))
(lock-camera camera)
(camera-lag 0.01)

(define nexttime 0)

(define (update)
        (cond ((< nexttime (time))
            (set! nexttime (+ (time) 0.1))
         
         ; move the camera
            (grab o)
            (let ((t (pdata-get "p" (modulo (- (turtle-position) 1) (pdata-size)))))
            (grab camera)
            (identity)
            (translate t)
            (ungrab))
         
         ; regenerate the shape
            (shape 12 1)
            (recalc-normals 0)
            (ungrab))))

(every-frame (update))

</file>

{{http://www.pawfal.org/dave/images/retreat/Screenshot-8.jpg|Screenshot-8.jpg}}


-- [[Dave Griffiths]]  - 16 Sep 2006