Bulge in a pipe

[LeviFiction]

Hello,

I'm not sure how best to search for this topic so i wasn't able to determine if this has been asked before. I'm looking to animate a bulge traveling down a tube, like in classic cartoons when someone too bug for a pipe is traveling down it. Or a hose with a big bulge of water traveling down it just before an unrealistic amount of water comes out. Trying to find a good way to do that wave/undulation effect.

I've tested the concept using a masking group. The bottom layer has two rectangles on it separated by the pipe width. The pipe itself. And then just a simple circle. I set the bottom layer as the mask added invisibly and just move the circle along the pipe. It works well enough with a straight pipe provided there are no color variations. So I can't make the pipe very detailed.

Just wondering if anyone has some ideas on a better way to do a distortion like this.

I'm using Moho Studio 12.5

Example of what I've done: https://drive.google.com/file/d/1WvL_B8 ... sp=sharing

[hayasidist]

How about:


that's two vector layers:

> mesh - a triangulated mesh - not visible (clear the "eyes" icon in the layer window)
> pipe - the long edges have 12 points - ends are peaked; middle 10 are curved; set to use mesh as a smart warp layer

on frame 0: mesh is over the middle of the pipe
on frame 1: shift the points in mesh to give a bulge that you like … then
(still on frame 1): move (translate layer) the layer mesh so that it's clear of the pipe on the left … then
on (e.g.) frame 100: move the layer mesh so that it's clear of the pipe on the right
press play
and then alter the number of points on the long edges of the pipe shape and/or adjust the animation of mesh points / layer translation to give you exactly what you want.

here's the file: https://www.mediafire.com/file/05e923j7 ... .moho/file

and there will be other ways...

[synthsin75]

How about:
and there will be other ways...

I think you nailed the best, most flexible way to do it, Paul.

[LeviFiction]

Wow, that's fantastic. Thank you so much for the example and explanation.

I've seen several posts on here using Smart Warp Meshes for things. Still had not occurred to me to use them this way. Will definitely have to learn more about how they work.

Thanks again.

Levi

[hayasidist]

@Levi - Glad to help.
@Wes - thanks for kind words.

[Greenlaw]

Just for fun, here's a variation using an SBD:





Basically, I'm using pin bones to push the points in the pipe. To do this, I selected all the bones and made three keyframes, scaling from 100% to 200% and back again. Then I just offset the three keys for each pin bone so they scaled in sequence. Tip: place the pin bones between the rows of points rather than directly under them.

It could be made better (maybe by adjusting Curvature?) but I didn't want to spend my whole lunch break on this.

Here's the file:

Pipeanim