LOGO-L> 3-D creations

[Yehuda Katz <yehuka@beitberl.ac.il>]

Hello,

Like you, I enjoy too the flow of 3-D creations by mhelhefni. I would
like to add my feeling, that the achieving of eye-catching pictures is
done somewhat on account of "good" Logo programming. I mean mainly the
excessive unnecessary use of global variables (those MAKE statements).

To demonstrate my point, I took elhefni's Saddle program, removed all
the MAKE's, re-arranged a little bit here and there, and that's what I
got:

===================================================
to go ; Saddle
turnon3d cs ht
draw 14 10 first questionbox[input step (.5 - 1)][]
end

to turnon3d
perspective
setturtle -1
setxyz 1000 1000 1000
setturtle 0 
end

to draw :a :b :step
pu gridx :a :b :step
pu gridz :a :b :step
end

to gridx :a :b :step
for[x -:a :a :step][
   for[z -:b :b :step][
      setxyz :x*15 y*150 :z*15 pd]pu]
end

to gridz :a :b :step
for[z -:b :b :step][
   for[x -:a :a :step][
      setxyz :x*15 y*150 :z*15 pd]pu]
end

to y
op(:x*:x/(:a*:a))-(:z*:z/(:b*:b))
end
===================================================

I hope that the creativity of mhelhefni will bring us many more
interesting and beautiful projects.

Regards...

[[Yehuda]]

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