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Contents 1 Model 1 (Modified 3D Surface) 2 Model 1 (Modified 3D Solids) 3 Comments

[edit] Model 1 (Modified 3D Surface)

Because I do not know the Netlogo language too well, I am not ready to make a model of my own, so what I did was to Modified the 3D Surface model from the models library. In this model, I redesigned the shape, and I added the display-color slide bar and the speed slide bar.

globals [ time ]

turtles-own [ x-cor y-cor z-cor ]

to setup
  ca
  set time 0
  set-default-shape turtles "circle"
  cct number [
    ;; randomly distribute the turtles over the xy plane
    set x-cor random-float 120 - 70
    set z-cor random-float 50 - 10
    set y-cor 00
    move
    render
  ]
end

to go
  set time time + speed
  ask turtles [
    move
    render
  ]
end

to move ; turtle procedure
  set y-cor ( 5 * cos ( 5 * ( time + x-cor ) ) )
            + ( 5 * cos ( 5 * ( time + z-cor ) ) )
end

to render ; turtle procedure
  ; convert 3-space coordinates to screen coordinates
  setxy (x-cor + ( z-cor / 2 ))   (y-cor + ( z-cor / 2 ))
  ; make lightness/darkness proportional to height, for added 3D effect
  set color scale-color display-color y-cor -12 10
end

[edit] Model 1 (Modified 3D Solids)

In this model, I was trying to create a smaller sphere inside the big sphere and create all the adjusting features of its own. However, I did not get it to work.

turtles-own
  [x-pos y-pos z-pos p theta phi temp-alpha temp-beta temp-gamma]

to cartset [x y z]
  set p sqrt((x ^ 2) + (y ^ 2) + (z ^ 2))
  set phi (atan sqrt((x ^ 2) + (y ^ 2)) z)
  set theta (atan y x)
end

to go
  ask turtles
    [
     set theta ((theta + theta-velocity) mod 360)  
     render-turtle
    ]
end

breeds [sphere ball]
to setup
  ca
  create-custom-ball 500
     [
     set color yellow
     set p 20        
     set theta random-float 360   
     set phi random-float 180
     render-turtle
     ]
  create-custom-sphere num-turtles
    [
    set p shape-size      
    set theta random-float 360    
    set phi random-float 180
    render-turtle
    ]
end

to render-turtle
  calculate-turtle-position
  set-turtle-position
end

to calculate-turtle-position
  set y-pos (p * (sin phi) * (sin theta))
  set x-pos (p * (sin phi) * (cos theta))
  set z-pos (p * (cos phi))
end

to set-turtle-position
  ifelse (view = "side")                                     ; sideview
    [setxy x-pos z-pos
     set color scale-color display-color y-pos (- shape-size) shape-size
    ]
    [ifelse (view = "top")                                  ; topview
      [setxy x-pos y-pos
       set color scale-color display-color z-pos (- shape-size) shape-size
      ]
      [setxy (p * (sin phi) * (cos theta))              ; bottomview
             (- (p * (sin phi) * (sin theta)))
       set color scale-color display-color (- z-pos) (- shape-size) shape-size
      ]
    ]
end

[edit] Comments

So far the Netlogo system seems pretty interesting and the language seems easy to understand. The Primitives Dictionary is very helpful in explaining the commands.