Well, I've been a forum lurker and a off-and-on AM'er for too long -- figured it was time I learned the basics so I can really be an animator. Here is my first bouncing balls of different materials exercise. Thank you amarillospider for setting up this bootcamp!

Wow! That was superb. On to the next one as far as I'm concerned. Nice work.

Outstanding setup and execution Will.

For some reason the second ball drew my attention.
I've been playing it back and forth trying to figure out why.

On closer view I can see going frame by frame that it does slightly squash and bounce but I can't help but think there should be a second bounce to accentuate the first.

By this I mean to say that the obvious mass of the ball doesn't appear to be fully distributed and the force dissipated by the single small bounce. It may also be that you just need to add a frame or two to each of those for the eye to have time to register the effect. In that case one bounce might be adequate.

I'm picking where I have little reason to pick. You've done well. Really nice!

The third ball appears to be a liquid of some type... just not sure what kind as it seems to keep its shape pretty well. Did you have any specific type of liquid in mind with #3?

I think that's a wonderful bounce sampler! And entertaining to watch.

Ball #3 is obviously made of some unusual cartoon substance not found in nature or science

Some notes on the movie...

[attachmentid=21959]


Here's your first bounce with that one frame I mentioned gone. To me it looks snappier.

[attachmentid=21961]

Robert has identified the element that confused me for ball #2.
The stretch of the ball while falling indicates a different matter than the bounce at the end.
I had assumed that there was little stretch but watching Robert's critique shows there is plenty (he even suggests getting rid of it). You could go either way depending on whether you intent the ball to be somewhat flexible or solid. If more solid then less stretch and about the same amount of bounce. If flexible then more bounce.

Robert as usual has provided his magic which I for one can't get enough of!

Thanks for such terrific feedback Dhar, Rodney, and Robert. As Robert noted, the third ball is made of a cartoon material, but I was thinking of the floaty nature of soap bubbles and the bounce of balloons when animating it.

The second ball wasn't making me happy either so I'm glad you called me on it. Deleting any squash and stretch almost took care of the problem, though adding a subtle second bounce as Rodney suggested seemed to finish it off. Robert, the frame-by-frame markup was extremely helpful and I appreciate the detailed notes. I have to ask how you did it -- that's a very useful tool!

Here's a new version of the bounce:

Wow. Quick turn around.
It looks like you've incorporated the majority (if not all the critiques).
I'm impressed.

I'll look again but from my vantage point... this ones complete.

Edit: If there is anything still amiss it might be that the balls don't all seem to fall at the same rate.
Ball#1 and #2 look pretty close (maybe even #4) but #3 looks like its falling in slow motion.
Objects will fall at the same rate no matter their weight or mass (barring opposing forces/wind and friction).

It would be easy enough to measure their fall by adding frame lines across the image.

Investigating further...
The balls seem to fall at the following (approximate) frame rates.

Ball#1 10 frames
Ball#2 12 frames
Ball#3 21 frames
Ball#4 12 frames
Ball#5 less than 2 frames

Of course my money is on Ball#5!
It makes sense that as Ball#5 didn't start from the same elevation it probably had some acceleration going for it. Besides... its looks cool dropping in like that.

If Ball#3's drop was increased to 12 frames that'd finish this one I think.

Ball 3 is supposed to be very light weight -- like a balloon -- so air resistance will have a far greater effect and slow it's fall. At least that's the effect I was shooting for.

yes, I think the very slow fall tells us it is something different entirely.

There is an issue of "terminal velocity" in objects like that. They accelerate for a while then can't go any faster because the air resistance is too great. Probably not a factor in such a short animation.

That makes sense. If that's what you are after you've pretty much got it.
To avoid confusion it might be best to label the balls in same way (or put a tag over/under them to clarify).
In a full out animation there'd probably be an end tied or something.

I guess what I'm trying to say is that its hard to know what you are after... so when in doubt make it clear one way or another. The attachment it has to the liquid makes it fairly obvious that its a rather light object.

Its a lot easier to demo a balloon with helium I guess.

You've done well on this one Will. Very well. You should be proud.

Thanks to you both -- time to move on to the next exercise!

Here's a small exercise (using the ball with tail) to figure out the swing of the tail when the ball is moved. It needs some work so any suggestions are welcome. Thanks!