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3D Layers attached to string: physics of a drop?

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 3D Layers attached to string: physics of a drop? on Nov 10, 2009 at 12:57:46 am

Hello.
I know I may end up just doing this manually, but I was wondering if there is any kind of expression that would simulate, basically, a card with one end attached to a string, and how it would act when you drop it, bouncing around and settling (if that makes sense?).
I've done it before manually, and it came out pretty good, but there are many more objects this time. I'd rather see if I could do it with expressions, or maybe a plugin that can do this?

Also, what I'm trying to achieve is, I have 4 words (work, shop, about, contact) - I want each letter acting as if it were attached to a string, have the letters drop down, where they recoil a bit when they reach the "bottom." Sway a little before they settle, etc. I'd also want an animation where it looks like the letters are smacked a little (this would be the mouseOver animation). Hope this makes sense

Thanks for the help

 Re: 3D Layers attached to string: physics of a drop?on Nov 10, 2009 at 1:30:49 am

It's totally possible to simulate this using expressions:
The physics of rigid-body free-falling is pretty simple, you can get the formula from the high-school physics texts. It involves solving a quadratic equation. But the hard part is the collision detection, i.e. when the irregularly-shaped letter object bounces off the floor because the formula works for point-like objects. That makes it even more complex if you want the dropped object to rotate around its center of mass. It's totally doable given some manual parameter-tweaking, and it's guaranteed to be realistic because of the precision of the math.

Xinlai Ni
Software Engineer, Google Inc.

 Re: 3D Layers attached to string: physics of a drop?on Nov 10, 2009 at 3:24:46 am

Sure, you could make gravity perfect and all math perfect, but I think you could be 80% there with simple elastic expressions, some basic keyframing and wiggle with rubber bounce controlled by an animated slider box.

http://www.motionscript.com/design-guide/elastic.html
or

http://technicolorsoftware.hostzi.com/

 Re: 3D Layers attached to string: physics of a drop?on Nov 10, 2009 at 4:14:12 pm

[Nicolas Hansen] "Also, what I'm trying to achieve is, I have 4 words (work, shop, about, contact) - I want each letter acting as if it were attached to a string, have the letters drop down, where they recoil a bit when they reach the "bottom." Sway a little before they settle, etc. I'd also want an animation where it looks like the letters are smacked a little (this would be the mouseOver animation). Hope this makes sense "

Seems to me I've seen all that kind of mouse-generated animation available directly within Flash or maybe Dreamweaver. You see this kind of stuff often on the more advanced Web sites. there are several online forums that highlight the best of Flash interactivity and mouse-fired animation. Umm, I have no idea where this stuff lives, I have never used Flash and hope I never do.

bogiesan