create a pendulum swing

[Guest]

I am trying to create a slide showing the swing of a pendulum like you would
find in a clock. I can animate the pendulum but the line from the pendulum to
the top of the slide is the problem. Where the line attaches to the "ball" it
needs to follow the ball through its swing. However the top of the line needs
to be anchored in the center of the slide. How can I accomplish this?

 

[Guest]

you could alternate very fast (or faster) exits and entries of side-by-side
lines that have the starting point in the same place. time them to correspond
with the arch of the pendulum. the line would look somewhat blurred with this
effect...

 

[Bill Dilworth]

To do this well, you will need PowerPoint 2002 or 2003 and will need to
create an animated object with a hidden pivot point.

A pendulum (the real type) swings back and forth on a pivot point at the top
of the weight's string, so we will need to create a shape that appears to
swing at the end of a string and repeats back and forth from this pivot
point. Here are the steps:

1) Create a line from the pivot point to the weight in its far left position
2) Create the weight object (whatever looks right to you) at the end of the
line
3) Group these two objects
4) Copy the group
5) Paste the group as a new object and spin it 180 degrees
6) Move the new group so the ends of the lines (pivot points) are at the
same point. It is perfectly ok if this spills over the edge of the slide.
7) Change the transparency of the new group to 99% fill and 99% on all the
lines
8) Group the new group and the original
9) Apply the emphasis animation called spin
10 ) Change the settings on the animation to
about 45 degrees clockwise
smooth start,
smooth end,
auto reverse,
speed medium,
repeat until the end of the slide,
start with previous.
11) Try it and tweak the speed and degrees of the swing.

Post back if you need help with any of these steps.


--
Bill Dilworth
A proud member of the Microsoft PPT MVP Team
Users helping fellow users.
http://billdilworth.mvps.org
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vestprog2@ Please read the PowerPoint FAQ pages.
yahoo. They answer most of our questions.
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..

 

[rex]

Bill,

I got all this (I think) but I cannot seem to "pin" the pivot point. It
wants to rotate about the centre of the group!

What have I missed??

Rex

Melbourne

 

[Bill Dilworth]

You need to group the two groups together (the group that was made 99%
transparent with the group that is visible) before applying the animations.

I think you missed step # 8

Bill D.

 

[rex]

I must be having a bad day!

I have done all that, I can see both images swinging but it still swings
around the middle of the combined group. Just to be certain I am running
2002 SP3 on XP

rex

 

[Bill Dilworth]

Just to recap:

Group A:
Line - visible
"weight" - visible

Group B:
Line - 99% transparent
"weight" - 99% transparent

Group B was turned upside down, so the weigh is up and the tip of the line
in group B meets the tip of the line from group A. Think of two lollypops
joined at the bottom of the sticks. The upside down lollypop is clear (99%
transparent) so you can't see it well.

Group A and Group B are combined to form group C. It is important to
include Group B which is mostly transparent. Including the near invisible
Group B moves the pivot from the center of Group A to the end of the line in
group A.

The animations are applied to Group C (after A & B are grouped) so it spins
around the center of the larger group, which is where the two ends of the
lollypops meet.


Bill D.

 

[rex]

Gottcha!!

I had the two groups at right angles. duh!

Rex