Eliminating a shape while animating

[Hoptoad]

I animated a bubble popping using point animation. When the bubble pops, it creates a lot of bubble chunks. These bubble chunks should only persist for a fraction of a second, right? The problem is, I can't get rid of them. If I delete the points of a chunk at some point, the entire animated shape is deleted throughout time. And if I change the style of the bubble chunk's "shape" so that is displays neither a fill nor a stroke, the chunk vanishes throughout time.

My solution was to use STEP interpolation and drag the chunks off to the side, out of the view port, at the moment they should blink out of existence. It works, but is this the best solution?

I suppose I could place each bubble chunk on its own layer and make each layer invisible at some point. But I like having all the chunks on one layer...

What would you do?

Note: All the chunks don't vanish on the same frame.

Thanks.

[synthsin75]

Some things, like the need to change individual shape opacity, are better done with the regular style, rather than a saved style. That's the way I would do it. Since you're already using a saved style, step interpolated point motion is the next best thing. Creating more layers would be way down the list of desirable solutions, IMO.

[Greenlaw]

I would use FBF or a Switch layer for this, at least for the 'pop' part. It's only a few frames, right? Should be easy.

If you go with FBF, duplicate the frame a few times and delete or erase the bits you don't want in a given frame. You can move/reshape the remaining bits with the magnet tool.

Turn on Onion Skin to get the timing and positioning right.

Or, you can simply draw it as an FBF sequence.

[Hoptoad]

Thanks for the replies.

I had tried frame-by-frame with my previous bubble experiments. They were awful. I just can't seem to pop a bubble with FBF. I even watched the Poptoogi video on FBF bubble popping.

I'm not sure how to turn my bubble pop into an action. I'd like to make it into a lot of bubbles (of different sizes) that swell and pop. The swelling bubble is on one vector layer, and the exploding bubble is on another vector layer. I've only made bone layer cycles until now, so I'm perplexed. Do I need to make 2 actions?

The bubble is on my Share Your Work, by the way.

[slowtiger]

There's no canonical way to do this. Your Bubble is alright, maybe a bit slow in the pop for my taste.

What you could do: put all bubble layers into a switch layer: growing, pop frames (for each new number of elements a new layer), and crown. This way everything is neatly together and I can make an action of the switch keys. What I would do: create the popping part in TVPaint...

In Moho each element exists for the duration of the scene, to make it disappear you can
- switch to invisible
- animate opacity
- move outside screen
- scale very small (this may cause problems).
Those are the options.

As for research: google videos with "high speed film bubble pop" and "high speed film drop". I think there's even books out there aimed at anime SFX artists.

[Hoptoad]

Thanks for the information, slowtiger. Yeh, the popping is a little slow. I wanted my bubble to pop slowly, of course, but I think I over-did it. My next bubble will pop faster.

I like the idea of using switch layers for my next bubble pop experiment. Thanks.

Your idea about using TVPaint to animate got me thinking. I do some of my character design in Procreate, a drawing app. Nowadays Procreate can do animation. I may do my next bubble pop experiment there and import it into Moho...

On your suggestion, I watched a high speed video of a bubble being popped. Wow, bubbles pop extremely fast! Also, the popping of a bubble resembles the popping of a balloon. It doesn't explode into several big droplets, but contracts as one unit to a point opposite of the puncture.

In cartoons, bubbles often pop more slowly than in real life, and create big arcing droplets (see the bubbles in Rick and Morty's "The Vat of Acid Episode"). Funny how common that animation solution is.

Maybe my pop should be one frame instead of nineteen. That would be realistic and super-easy! Decisions, decisions.

[SimplSam]

Some great tips. Depending on the scene - you could also use animated shape ordering to send it/them behind a pseudo-background shape.

[Hoptoad]

Some great tips. Depending on the scene - you could also use animated shape ordering to send it/them behind a pseudo-background shape.

I can't figure out how to do that. I had tried on a previous animation thingy. I set Allow Animated Layer Effects, but that didn't help. How do you do that? I'd love to be able to change the order of shapes in mid-animation.

[SimplSam]

To enable this feature - look in the Vector Layer properties under Vectors

[Hoptoad]

Thank you. It didn't occur to me that it might be a feature that someone would want to turn off, and that it was turned off.

This is going to come in handy.

[Greenlaw]

Another trick might be to use an animated mask. Just create a shape in a lower layer with enough points in it so you can animate it to mask out the bits you want to 'disappear'. This is how I might handle it in After Effects, and it should work well for Moho too.

[Hoptoad]

Another trick might be to use an animated mask. Just create a shape in a lower layer with enough points in it so you can animate it to mask out the bits you want to 'disappear'. This is how I might handle it in After Effects, and it should work well for Moho too.

That is a clever idea. I think i could've figured out how to do that. Oh well, I'll file that solution away for next time.

I decided to use slowtiger's Switch Layer idea. I like Switch Layers, and it seemed like something that I could do quickly. I also thought it would be useful when it came time to make an Action for the purpose of creating a lot of popping bubbles on the canvas.

Unfortunately, apparently a Switch Layer can't be made into an Action. I exported the Switch Layer animation as an Action, but the Action would not function when imported. Am I correct that a Switch Layer can't be made into an Action, or did I do something wrong?

Could a bone be added to the Switch Layer that somehow makes its animation available as an Action?

Since I couldn't get Actions to work, I simply duplicated the Switch Layer multiple times, making a lot of bubbles.

The new pool of multiple bubbles are in the Share Your Work. They pop faster, which makes them more bubble-like.

[Greenlaw]

Unfortunately, apparently a Switch Layer can't be made into an Action. I exported the Switch Layer animation as an Action, but the Action would not function when imported. Am I correct that a Switch Layer can't be made into an Action, or did I do something wrong?

I use switch layers with Smart Bone Dials all the time. You just set the Switch layer keyframes inside the action, and they play in sequence like any keyframed animation inside a Smart Bone Action. The nice thing about this is you can control the speed or make it play backwards, or even non-linearly using the Smart Bone Dial.

A long time ago, I would use an SBD to animate a Switch layer for lip sync (nowadays, I prefer using the Switch Selection window for that.) And if you look at the Big Guy troll animation at the end of my 2019 demo reel, his hair animation is a switch layer with an image sequence of turning hair that I rendered from a 3D program, and it's controlled using the same Smart Bone Dial that turns his head. I've used this technique for animating FBF water splashes inside a Switch Layer too, so I could control the speed of the splashing, and vary it at different locations.

Hope this helps.

[Hoptoad]

Oh! Thank you. I forgot how versatile SBAs can be, since I only use them to help bend elbows, knees, and the like.

Top notch demo reel, ranks amongst the best I've seen.

[Greenlaw]

Re: SBAs, Oh, definitely! I don't think I'd be using Moho at work if it wasn't for Smart Bone Actions and Dials. It's one of the things that sets Moho apart from other 2D animation packages.