Animate with expression

Discussions about animating in SOFTIMAGE©
funky75
Posts: 46
Joined: 08 Oct 2012, 11:03

Animate with expression

Post by funky75 » 03 Apr 2018, 09:15

Hi guys,
i would like to animate a parameter but I don't know exactly the syntaxe to use.. I would like a progressive noise going from 0 to 5, I want to simulate a neon progressively lighting a scene..

Any help would be appreciate.
Thank you

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Mathaeus
Posts: 1715
Joined: 08 Jun 2009, 21:11
Location: Zagreb, Croatia

Re: Animate with expression

Post by Mathaeus » 03 Apr 2018, 11:49

Once you're in expression editor, just choose the noise function from menu (function > random or something like, I'm not in front of SI now). It should create something like
noise ( <x>, <y>, <z> )
You should replace <x> (and <y> and <z>), by any value that changes over time. Some practice was Fc , which is current frame number, however it could be animated position of some null, like mynull.kine.local.posx . Animated null will give you better control. That will return the noise between 0 and 1. To get animated from 0 - 5 range, you can multiply it, so final expression could be something like
(noise ( mynull.kine.local.posx, 0, 0 ))*mynull_b.kine.local.posx
Now, instead of setting an expression directly into intensity parameter, you could set it into Scalar Save State node in Render Tree, put output into Change range node, and into Intensity of light at the end - that should give you easier control over remapping the noise output.
The renderer "turtle" used by this scene, is not currently available. The "turtle" renderer will be used instead.

funky75
Posts: 46
Joined: 08 Oct 2012, 11:03

Re: Animate with expression

Post by funky75 » 03 Apr 2018, 12:57

Thank you Mathaeus!!