Basic scripting question.. 2005-04-15 - By Matt Lowery
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Hey glad to see that see someone has taken the time to up date nullifier. (
the first piece of code I ever wrote.) I wrote it way back in 2000 ( long
before the match all transforms command) and was still on a steep learning
curve with scripting when I did it, but it ended up being a useful tool and
I still use it on an almost daily basis.
Anyway, no offence taken at all Kim. Thanks for the suggestions.
-- --Original Message-- --
From: owner-xsi@(protected) [mailto:owner-xsi@(protected)]On Behalf Of
kim aldis
Sent: Friday, April 15, 2005 12:50 PM
To: XSI@(protected)
Subject: RE: Basic scripting question..
I'm waiting for stuff to happen so I figured I'd convert it to the OM and
JS, add a few bells and whistles and pass some comments. No offence intended
to matt or anything but I thought it'd be a good opportunity to add some
notes on good coding and tool building practice. The finished piece is
below:-
*
I'm just copying the transform, as already suggested. This will copy
scales and rotates too. It's equally possible to copy just posx, et al, if
you just want positions.
*
I've used an Enumerator loop. As Brad points out in his 'Loopin
Lizards' piece, this is by ar the quickest way to loop through a list. Add
ro this, it's all OM so now command logging = fast. You'll really notice the
difference when you're up to 500 objects, it may even make the difference
between you doing it and deciding it'snot worth it.
*
code is commented. Doesn't matter how short the piece is, *always*
meaningfully comment your code.
*
I've used meaningful names. var A = and var B = is just going to
become a nightmare in anything longer than 20 lines or so. Note also, I've
prefixed variable names with an 'o', for 'Object'. adding meaningful
prefixes to variables tells you what type they are. s for string, a for
array, yadda, yadda.
*
Short, isn't it. But it does show how much you can simplify things
with a bit of understanding and forethought. And, short code means legible
code and legible code is god.
*
I've turned it into a function which returns the created hierarchy
root. This makes it modular, easy to include in other scripts, lets you
start library-fying your work so you can reuse it. It also makes it easier
to manipulate the result later in the script - see the shift line just ater
the function call.
*
I've gone to a bit of trouble to name the nulls after the objects
they've taken their transforms from. I can't emphasise this enough, ALLWAYS
MEANINGFULLY NAME YOUR OBJECTS. especially when you're potentially making a
lot of them, as in this script.
*
Lee was absolutely right to ask how to make this script parent the
nulls and name the root. You simply can't have hundreds of objects, "Null1,
NUll2 ......." kicking around in the root of your scene. This is just common
sense even if you're not scripting. Sorry to bang on, but I see *so* many
people just build flat, non-hierarchical models. It's sloppy and it'll slow
you down more than you could possibly imagine.
*
Jscript is easier to work with when your code starts getting longer.
Enjoy.
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// nullifier v1.1 by Matt Lowery
//
// adapted to OM and JS by Kim Aldis, 15/4/05.
// <http://www.cg-soup.com> www.cg-soup.com
////////////////////////////////
var oNulls = Nullifier( Selection );
oNulls. posx = 123;
function Nullifier( oSel ) {
// create the root null for our hierarchy of nulls.
var oRootNull = ActiveProject.ActiveScene.Root.AddNull( "RootNull" );
// way fastest way of looping through a selection.
for (var i = new Enumerator( oSel ); ! i.atEnd(); i.moveNext() ) {
var oSourceObject = i.item();
// make a null, name it after this selection item.
var oNull = oRootNull.AddNull( oSourceObject.name + "_Null" );
//copy the transform over from selection item to the new null
oNull.kinematics.local.transform =
f.item().kinematics.local.transform;
}
return oRootNull;
}
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