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# Slowing down rotation of a circle to fit 1 second of animation,

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 Slowing down rotation of a circle to fit 1 second of animation, on Aug 31, 2011 at 4:33:40 pm

Hello, could anyone tell me how to go about,
adding a looping composition containing a circle having 10 degree/sec rotation over 18 seconds to a composition of 1 second while maintaining its slow velocity.

(shortening the clip causes the velocity to speed up)
It I just add it to the 1 second composition the 18 second clip is prematurely cut)

Any help greatly appreciated!

 Re: Slowing down rotation of a circle to fit 1 second of animation,on Aug 31, 2011 at 4:50:37 pm

Are you saying you want an 18 second animation to complete the entire animation in only 1 second, but not to go any faster?

- The Great Szalam
(The 'Great' stands for 'Not So Great, in fact, Extremely Humble')

No trees were harmed in the creation of this message, but several thousand electrons were mildly inconvenienced.

 Re: Slowing down rotation of a circle to fit 1 second of animation,on Aug 31, 2011 at 5:00:04 pm

You can't do what you want. Take a minute to think:

Rotation is simply motion of an object around a central point. Velocity or speed -- call it what you want -- is a function of distance of movement and length of time.

If an object moves a short distance in a given time, it moves slowly. If the object moves a greater distance in the same amount of time, it moves faster.

If the object moves a given distance over a long time, it moves slowly. If the object moves the same distance in less time, it moves faster.

Your object rotates a given amount over 18 seconds. Now you want it to rotate the same amount over 1 second. You are asking for a physical impossibility.

Unless you know how to change Einstein's laws of time and space, of course.

Dave LaRonde
Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA

 Re: Slowing down rotation of a circle to fit 1 second of animation,on Aug 31, 2011 at 5:49:18 pm

Thank you for your replies,

Yes I see the impossibility but I thought I'd go into details and see if that changes anything (except time and space :)

Well my final composition is 1 second in duration. It contains an particle effect animation that loops once/second
Above this I want to place a rotating circle that rotates slowly in its own timeline (i.e slowly 10 degrees/sec over 18 seconds, i.e it rotates once per 18 seconds)

I've had to keep the circles rotation going over 18 seconds just to slow it down. (is this the only way to slow rotation?)

Would the only workaround be having my 1 second looping particle effect extend over the 18 seconds it takes the circle to complete one rotation?

Or is there a way to maintain the duration of my composition at 1 second and slow down the circles rotation.
(i.e by the time the particle effect loops 18 times, the circle shall complete 1 rotation, but the timeline duration shall be maintained at 1 second)

 Re: Slowing down rotation of a circle to fit 1 second of animation,on Aug 31, 2011 at 6:06:13 pm

*Quote*
Also in case I have to add my 1 second looping composition to a new 18 second composition containing the circle, is there a way to do it without having to duplicate the 1 second loop and manually add it 18 times to the composition?

 Re: Slowing down rotation of a circle to fit 1 second of animation,on Aug 31, 2011 at 7:27:43 pm

[Nikhil Rath] "Would the only workaround be having my 1 second looping particle effect extend over the 18 seconds it takes the circle to complete one rotation?"

Yes (unless the circle has symmetry).

If you need 18 seconds to make something loopable, it won't be seamless unless it's the full 18 seconds.

Walter Soyka
Principal & Designer at Keen Live
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
RenderBreak Blog - What I'm thinking when my workstation's thinking
Creative Cow Forum Host: Live & Stage Events

 Re: Slowing down rotation of a circle to fit 1 second of animation,on Aug 31, 2011 at 8:31:38 pm

What does your circle look like? If it is (or can be) a wheel with 18 spokes, you could rotate 1/18th of a revolution such that the ending location of one spoke, matches the starting location of the next. When looped, it will appear to be making a full rotation, though in reality it is only rotating a small amount.

-Matt

Need a quick break from motion graphics?
Try my game Constellation at:
http://www.paperdragongames.com

 Re: Slowing down rotation of a circle to fit 1 second of animation,on Aug 31, 2011 at 8:54:54 pm

Actually the circle is a disc with lettering which isn't repetitive in any way.
However I managed to get it to loop, but had to increase the duration to 18 seconds to accomodate the rotation of the disc.
Also with regards to my previous question, is there a simpler way to add the 1 second composition 18 times to the main composition, i.e to match its duration with that of the circle?
Like a duplicate and layer offset expression (offset on the timeline I mean)

 Re: Slowing down rotation of a circle to fit 1 second of animation,on Aug 31, 2011 at 9:06:52 pm

[Nikhil Rath] "Also with regards to my previous question, is there a simpler way to add the 1 second composition 18 times to the main composition, i.e to match its duration with that of the circle?"

Add your 1-second precomp to the 18-second main comp. Enable time-remapping on the precomp, then Alt-click the Time Remap stopwatch and enter the expression:

`time % 1`

This will make the comp start over at the top of each second.

Alternately, you can can use loopOut("cycle"), but you may need to fiddle a little with the start and end of the precomp's time remapping to get a seamless loop.

Walter Soyka
Principal & Designer at Keen Live
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
RenderBreak Blog - What I'm thinking when my workstation's thinking
Creative Cow Forum Host: Live & Stage Events

 Re: Slowing down rotation of a circle to fit 1 second of animation,on Aug 31, 2011 at 8:58:24 pm

Most artists are familiar with the notion of reflectional symmetry (where a figure appears the same when reflected over an axis or plane), but I was referring to what Matt described way better than I did -- rotational symmetry (where a figure appears the same when rotated a certain amount around a point). My apologies I wasn't clearer!

Walter Soyka
Principal & Designer at Keen Live
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
RenderBreak Blog - What I'm thinking when my workstation's thinking
Creative Cow Forum Host: Live & Stage Events