Forward

Traditional Logo had new users build a house as an introduction, but due to turtleSpaces’ 3D nature, starfields are much more impressive, so we’ll start there.

▶ View interactive demo

Click and drag the window above to see all the stars!

Cool huh? First, we’re going to create this simple starfield that wraps around the camera position.

We’ll start by creating the procedure:

TO stars
END

Then we’ll add in some setup stuff:

These procedures draw a simple tree in a classic Logo lined style, and a forest of these trees. First, let’s take a look at the tree procedure as a whole.

TO tree :scale
  slideleft 8.25 * :scale
  forward 20 * :scale
  repeat 4 [
    slideleft (10 * (5 - repcount)) * :scale
    left 30
    slideright (12 * (5 - repcount)) * :scale
    right 30
  ]
  left 30
  slideright 5 * :scale
  right 60
  slideright 5 * :scale
  left 30
  repeat 4 [
    right 30
    slideright (12 * repcount) * :scale
    left 30
    slideleft (10 * repcount) * :scale
  ]
  back 20 * :scale
  slideleft 8.25 * :scale
END

Now let’s go through it a line at a time. The procedure starts out with the procedure declaration TO , then the name of the procedure tree, then a single parameter, :scale