Page 1228 - Kitab3DsMax

Part XII: MAXScript and Plug-Ins
Loops
A loop is a MAXScript construct that lets you override the normal flow of execution. Instead of processing
each line in your script once and then quitting, Max can use loops to do something several times.
For example,
j = 0
for i = 1 to 5 do
(
j = j + i
)
This MAXScript uses two variables—i and j—but you can use any variables you want in your loops. The
script sets the variable j to 0 and then uses the variable i to count from 1 to 5. Max repeats the code
between the parentheses five times, and each time the variable i is incremented by 1. Inside the loop, Max
adds the current value of i to j. Can you figure out what the value of j is at the end of the script? If you
guessed 15, you’re right. To see why, look at the value of each variable as the script is running:
When j i
----------------------------
First line 0 0
Start of loop 0 1
After first loop 1 1
Start of second loop 1 2
After second loop 3 2
Start of third loop 3 3
After third loop 6 3
Start of fourth loop 6 4
After fourth loop 10 4
Start of fifth loop 10 5
After fifth loop 15 5
A loop is also useful for processing each member of an array or collection. The following MAXScript shows
one way to turn every teapot in a scene blue:
teapots = $teapot* -- get the collection of teapots
for singleTeapot in teapots do
(
singleTeapot.wirecolor = blue
)
You can use a for loop to create a bunch of objects for you. Try this MAXScript:
for I = 1 to 10 collect
(
sphere radius:15
)
The collect keyword tells Max to create a collection with the results of the MAXScript in the block of
code inside the parentheses. The line
sphere radius:15
tells Max to create a sphere with radius of 15, so the entire script created 10 spheres and added them to your
scene. Unfortunately, Max puts them all in the same spot, so move them around a bit so you can see them:

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