CGTalk Inertia bounce in Maya
 08-19-2013, 02:59 PM #1 artcross Frequenter portfolio Jonathan Reyes New York City, USA   Join Date: Jan 2007 Posts: 108 Inertia bounce in Maya I've been using an expression in after effects that calculates inertia based on 2 keyframes on a given property. You can find the expression here under inertial bounce: http://www.motion-graphics-exchange...s/4ad0f32a944ad I'm not too keen on scripting in Maya, so I was wondering if it's possible to convert this expression to something Maya can use. Here's the expression if the link isn't working: // Inertial Bounce (moves settle into place after bouncing around a little) n = 0; if (numKeys > 0){ n = nearestKey(time).index; if (key(n).time > time){ n--; } } if (n == 0){ t = 0; }else{ t = time - key(n).time; } if (n > 0){ v = velocityAtTime(key(n).time - thisComp.frameDuration/10); amp = .05; freq = 4.0; decay = 2.0; value + v*amp*Math.sin(freq*t*2*Math.PI)/Math.exp(decay*t); }else{ value; } Thank you! share quote
 08-20-2013, 05:36 AM #2 ristopuukko Earthling   portfolio Risto Puukko Senior fx td FrameStore London, United%2BKingdom   Join Date: Nov 2003 Posts: 814 http://download.autodesk.com/global...mber=d30e327698 __________________ - Oh no, it's me - share quote
 08-20-2013, 03:52 PM #3 artcross Frequenter portfolio Jonathan Reyes New York City, USA   Join Date: Jan 2007 Posts: 108 Not quite what i'm looking for. This expression would take 2 keyframes and calculate inertia, then automatically create a sort of decaying sine wave until it settles into the value of the last keyframe. For example, if i added it to 2 rotation keyframes, it would overshoot the last value of the keyframe, then bounce back to a little before the value of the last keyframe, the bounce forward again etc. until it finally settles into place. It could be applied to any keyframe w/ numerical value including scale, position, rotation, even bend handle values, etc.. share quote
 08-20-2013, 04:39 PM #4 mustique Expert copywriter   Join Date: Jul 2002 Posts: 2,017 There's an usefull free set of tools called red9 for animation purposes, it has a key randomizer feature, well take a look and decide by yourself http://red9-consultancy.blogspot.co...filter-and.html __________________ "Any intelligent fool can make things bigger, more complex & more violent..." Einstein share quote
 10-03-2013, 05:50 PM #5 artcross Frequenter portfolio Jonathan Reyes New York City, USA   Join Date: Jan 2007 Posts: 108 Thanks mustique, finally had a chance to check out that pack and while definitely useful, isn't what I'm looking for. share quote
 06-24-2014, 02:51 PM #7 RickToxik Expert   portfolio Eric Mc Guire Canada   Join Date: May 2010 Posts: 560 You'll be a happier man if you buy Maya MASH: https://mash.mainframe.co.uk/ I have lost track of all the things you can do with it, but inertia effects is one of them since the beginning (the spring node). Also, the guy who is behind MASH I believe is one of the few who made an inertia expression for maya many years ago. I am serious, MASH is one of the top plugins ever invented for maya : ) share quote
06-24-2014, 10:56 PM   #8
djx
Where's my pony?

David Johnson
vfx & creature td
Melbourne, Australia

Join Date: Jun 2003
Posts: 3,464
Adam Burke wrote a script years ago called jabPendulate that did something similar to what your expression does. I cant find it online anywhere, so I hope Adam doesn't mind me uploading it here.

If you feel like spending \$35, Chad Vernon has a great jiggle deformer tutorial on cgcircuit that would really be of interest to you if you did want to learn some python api coding. Possibly too advanced if you are just starting out. Or maybe not. The deformer works on component level, but he also does some prototyping that shows the same math applied at a transform level. Its a great tutorial

David
Attached Files
 jabPendulate.zip (1.3 KB, 45 views)
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