Rocket Orbit

This simple commented project allows for the introduction of 3D movements and shapes (the rocket procedure) including a basic introduction to repeat, the creation of turtle models and the use of premodel, an introduction to the orbit primitives and the use of a new worker (thread) for orbiting the camera!

TO rocket
  forward 70
  down 90
  ;these two commands orient the rocket better for use as
  ;a turtle model
  setfillcolor yellow
  ;yellow is a function that returns the value 13
  ;it is a shortcut used for convenience in learning
  ;as is red, green, blue etc.
  cylinder 20 120 10
  ;cylinder takes   
  rollright 180
  ;flip the turtle over to create the nose cone
  cone 20 50 10
  lower 50
  ;lower the turtle to create the 'nose'
  setfillcolor red
  icosphere 3
  setfillcolor orange
  ra 50 + 120
  ;ra is short for raise
  rr 180
  ;rr is shorthand for rollright
  cutcone 20 30 30 10
  ;move the turtle to the bottom of the rocket and
  ;create the tail
  up 90 bk 30.1
  ;bk is short for back
  setfillcolor white
  repeat 2 [cylinderslice 40 5 20 10 rr 90]
  ;create the fins
  setfillcolor red
  dn 90 sl 10 bk 10 cylinder 10 10 10
  ;sl is short for slideleft
  fd 20 cylinder 10 10 10 sr 20
  ;fd is short for forward
  ;sr is short for slideright
  cylinder 10 10 10 bk 20 cylinder 10 10 10
  ;create the jets

TO createmodel
  ;cs is short for clearscreen
  begintag "rocketmodel
  ;tags are used to create turtle models
  ;among other uses. You can also use them to
  ;show or hide parts of the 'turtle track'
  ;run the rocket procedure
  ;close the tag
  newmodel "rocket "rocketmodel
  ;create a new model called 'rocket' based on the
  ;rocketmodel tag
  setmodel "rocket
  ;set the turtle's model to the rocket model
  ;clear away the tagged model, leaving only the

TO starfield :number
  ;suspend rendering of the scene until we're done drawing the stars
  repeat :number [
    randomvectors randomfillcolor
    ;randomvectors orients the turtle randomly
    ;while randomfillcolor sets a random fill color
    forward 1000 + random 1000
    ;move forward a random distance
    up 90
    ;orient the turtle up in preparation of creating a spot
    ;because the spot is created around and below the turtle
    spot 10 + random 10
    ;create a randomly-sized spot
  ;resume rendering

TO main
  ;resets turtleSpaces to a default state
  ;execute the createmodel procedure
  starfield 200
  ;execute the starfield procedure, passing the parameter value 200
  setmodelscale 0.5
  ;decrease the size of the turtle model to half normal
  setpremodel [lt 90]
  ;inserts 'left 90' into the turtle track between the scene
  ;and the turtle model ('pre' the model)
  setfillcolor 14
  ;sets the fillcolor to 14. Type 'showcolors' or 'sc' in the console
  ;to see a list of default colors. You can also definecolor your own!
  ico 50
  ;create an icosphere (the planet)
  ;set the 'anchor point', or the point the turtle 'orbits' around
  ;using the orbit commands, to the current turtle position
  pullout 80
  ;pull away 80 turtle units from the anchor point
  snappy:newworker [forever [orbitleft 0.1]]
  ;tell snappy the camera turtle to create a new routine or thread
  ;that forever orbits around the scene to its left one tenth of
  ;a degree at a time
  make "rotation 0
  ;define a container (variable) called 'rotation'
  ;and set it to 0. We're going to use it to keep track of the
  ;rotation of the rocket
  forever [
    inc "rotation
    ;same as make "rotation :rotation + 1
    ;there is also dec (decrement)
    setpremodel {"lt 90 "rollright :rotation % 360}
    ;curly braces indicate a 'softlist', a list that is evaluated
    ;at runtime. In this case, so that we can have a dynamic
    ;rotation value we pass to setpremodel
    ;% is shorthand for modulus
    orbitleft 1
    ;orbit the rocket one degree to the left
    wait 1
    ;wait one sixtieth of a second