Workshop I: Bouncing Ball

[Nichod]

I thought it might be an interesting way to get the creative juices flowing for everyone, as well as a learning experience. So I'm going to post up a series of "Workshops" that everyone (or no one) can participate in. The best place to start is with the simple bouncing ball animation. (or in this case a marble A good example can be found here.

I can see this being accomplished by three different techniques:

1. Hand scale and rotate the ball (marble) at the desired keyframes and inbetweens and let Moho interpolate portions of the animation

2. Create a bone in the ball and animate by positioning, rotating and scaling the bone

3. Animate it all frame by frame via switch layers.

Good luck. Will post mine up soon.

Brian

[Nichod]

Ok. Excuse the Moho demo watermarks:) Still making sure Moho can do what I am looking for.

Bounce.
*divx codec and its less then 300 kb*

Still have to play with the timing again. I hope some others get in on this.

Brian

[Benvindo]

I maded one with the

"1. Hand scale and rotate the ball (marble) at the desired keyframes and inbetweens and let Moho interpolate portions of the animation "

but diddn`t like it
The timing is wrong,have no flexibility,etc,etc.

..anyway...I mixed my ani with your ani
the result is at
http://drnmk.host.sk/bouncing_ball_01.htm

I`ll try to make another bouncing ball

Benvindo

[Nichod]

Interesting mix. I like the end with the ball bouncing on the little pole. Needs some squash and stretch there though. When I get my bounce a bit more refined I'll upload it as a demonstration file. One nice thing that I found in Moho during this, which I may have missed in the manual. Is how you can click below the frame position and set where onion skinning takes place. Very handy and wonderful feature.

Brian

[Rasheed]

Here is my attempt (441 Kb). Ball bounces less and less until it stops (while the cloulds are moving by). There's a zipped Moho file as well, here.

I did the bouncing of the ball this way (keyframes refer to the Point Motion and Selected Point motion channels):
1) daw a round ball (circle)
2) put the ball at the extreme positions (top, bottom), at the appropriate keyframes; use union skinning to determine the correct positions
3) put key frames before and after the bottom positions
4) flatten the ball in the bottom positions with the Move Points tool, but leave the bottom point alone, so the ball stays on the floor
5) in the keyframes surrounding the bottom positions, rearrange the points so, that the ball points along its path of movement, use union skinning to help you
6) put keyframes halfway between the top and bottom positions and move the ball towards the top positions (but keeping track of the path by using union skinning of both top and bottom positions), so the ball slows down when it reaches the top of its path and accellerates when it reaches the bottom of its path
7) always remember when rearranging the points that the total volume of the ball should remain the same and there should be enough symmetry in the ball shape left, so it always resembles a ball.

Edit: to save bandwidth (and server space) I compressed the Quicktime file with the DivX codec to 27 Kbytes.

[Rasheed]

1. Hand scale and rotate the ball (marble) at the desired keyframes and inbetweens and let Moho interpolate portions of the animation

I don't think that will work on seperate points, because in my experience scaling and rotating shapes will distort your ball shape in the inbetweens. And if you use layer scaling, rotation and translation, you make things unnecessarily complicated.

Note I should be very cautious here, because I've been so wrong about many things lately. It seems knowledge only comes after a decent portion of self-doubt (knowing that in essence you know nothing).

[Rasheed]

Bounce.

I like the directness of it, but IMHO it could use some improvements here and there.

The ball not only changes shape, but also changes volume. I don't think that's right, is it? And at the end the ball comes to a sudden stop, while in the earlier part of your anim the ball seemed to be a non-rigid object. Shouldn't there be a little bit of "wobbling" to release the last bits of kinetic energy from the ball?

[Nichod]

I don't think that will work on seperate points, because in my experience scaling and rotating shapes will distort your ball shape in the inbetweens. And if you use layer scaling, rotation and translation, you make things unnecessarily complicated.

Mine was done with hand scaling and rotation. And the point of doing this is so it will to an extent calculate the inbetweens for you. Yeah I wouldn't use layer scaling, etc. overly complicated.

Brian

[Nichod]

I like the directness of it, but IMHO it could use some improvements here and there.

The ball not only changes shape, but also changes volume. I don't think that's right, is it? And at the end the ball comes to a sudden stop, while in the earlier part of your anim the ball seemed to be a non-rigid object. Shouldn't there be a little bit of "wobbling" to release the last bits of kinetic energy from the ball?

I agree on the wobbling. I can see a few ways I could do this. Can go with a realistic release via a series of descending bounces, or a sticking jello wobble effect. I agree it needs some work, pleased with it for being a 5 minute quickie. Not sure if the volume changes to a noticeable extent, but I'll take another look at it. Thanks for the crit. Will check out yours when I get home and can view quicktime.

Brian

[Nichod]

Here is my attempt (441 Kb).

Not bad. Bouncing seems a bit stiff at the end. And the ball doesn't touch the ground on the first bounce, but overall a nice job.

[Rasheed]

I will correct that soon.

Here is another one, Quicktime w DivX (49 Kb), the Moho source is here.

[Rasheed]

Here is the improved version of my bouncing ball (Quicktime, DivX, 21 Kb). Now there is a logical reason why the ball doesn't happily bounce on; it gets stuck in something sticky. The Moho source is here.

[Rasheed]

Hmm, should I make an animation of a ball falling towards water, which stops to feel if the temperature is right. And because it's too cold, it decides to jump up again, pushing off from the water. Or a whole buch of balls falling down from different heights and angles, or, or. Well, the possibilities are endless.

Edit: How about this one (Source)? Sorry for the rather poor SFX, I'm just a beginner.

Anyone any crazier ideas with the ball animation? Bigger and bigger balls eating the smaller ones, while bouncing.

[Nichod]

Here is the improved version of my bouncing ball

I'd add a little stretch on the last bounce. And the wobble is nice at the end in the hole, but somehow I think it should show some roll as well. Looks nice.

Brian

[Nichod]

Here is another one, Quicktime w DivX (49 Kb), the Moho source is here.

Cute. The thing that bothers me with that one is that it shatters, but the pieces barely bounce, and they don't roll realistically. I'll have to wait to work on mine, have a busy weekend.

Brian