Get a wriggle on

chucky · Post by **chucky** » Mon Feb 02, 2009 5:43 am

Ok here's a old old issue I have with AS.
You could even call it baggage.

I think an illustration will serve best to explain what I would like to achieve more easily with bones/ scripts than frame by frame animation.
Please excuse the scrappiness.

See that the corner of the shape should move down the path of the spine, but clearly, everything will go A over T .
I was hoping Vern's new path script might help but I can't quit visualise the implementation as yet, it may be the answer to an age old problem.....
Anyone got any ideas about this being achieved with bones/ scripts?

Obviously the difficult part is the vertical lines that join to the wriggling spine, think about it , it's a curly one.

slowtiger · Post by **slowtiger** » Mon Feb 02, 2009 12:05 pm

Short answer: No way.

Long answer: As simple as that wave pattern is for every decent physics simulation software, the perspective you need makes it totally complicated.

The easiest automatic solution would be in a 3D program.

Let's analyse. There's 2 parallel wavy lines which could be animated with a lot of bones and the right settings for springiness etc. So far, I think it's possible to do that in AS, with bone dynamics and bone angle controls (one line controlling the other).

The tricky thing is to get the vertical line segments attach and move correctly, and create the correct shapes from that. It would requite to:
- attach a vertical line to the wavy lines
- shift it down those lines while maintaining the correct perspective
- get 2 line segments from the wavy lines and 2 vertical lines and make that into a shape.
(and that's just one shape.)

As you know, I don't script or use too complex rigs, but I think I'm right with this.

chucky · Post by **chucky** » Mon Feb 02, 2009 12:18 pm

Have you seen Vern's point group to point path script discussion Slowtiger?
I am thinking the shapes on the far side, especially that troublesome vertical could travel down the "spine" of the wriggle, half of the shape might not need to be attached to the rest of the "spine" just tucked away as a lower shape.
I always knew this had been out of the grasp previously of AS , I am hoping now that it may be possible.

Genete · Post by **Genete** » Mon Feb 02, 2009 12:56 pm

One thing is that a vertex can be "soft linked" to an existing line using a script and other is that you can create a shape using that "soft link". I think that it would imply a depth modification of the way shapes are created. Current chapes are created on "glued set of lines" (their points are glued). If the point is "soft linked" how would the shape will be created? Shapes and segments (portion of line between two points) are hardly related in the definition of the shape. I'm not telling that it is not possible but I believe that additional tricks or core software modification is needed for the thing you want to do.
-G

chucky · Post by **chucky** » Mon Feb 02, 2009 4:42 pm

Thanks for answering guys.
If images are down for a while today, it is because my website server is undergoing some significant rebuild today, sorry about that.
I think the issue we have been discussing is an area where AS definitely shows a crack in its generally robust armour.
We can normally find ways around things in AS, but I think this one is a 'doozy' .

chucky · Post by **chucky** » Wed Feb 04, 2009 3:39 pm

In 3D this is easy, that is a given. I guess switches are the only way. Damn shame, I was hoping for one of those lateral thinking solutions, using the existing AS version, that I, for all my ponderings on this, may have missed.
Poo.....

Thanks for all the thoughts, I particularily liked Genete's idea no matter how 'futuristic' it may be. I guess that's the advantage of Synfig is that good scriptors can individually develop such ideas if they wish.
Well who know's what AS6 will bring.

heyvern · Post by **heyvern** » Wed Feb 04, 2009 6:17 pm

I'm having a bit of trouble trying to grasp what you want that point to do. Travel down the spline? Which spline? The long wiggly one or the vertical short one? Are you looking for automation of the entire wiggle or just the shapes that create the "3d" effect of the wiggling ribbon?

I think slowtiger is on to something. The motion of the points isn't really follow a spline, it is defined by some formula and... uh... wait a second...

OH CRAP!

It just popped into my head what you are asking!!! I get it I get it. You want that little green shape to "travel down" the spline. It would be a separate mesh or group of points. It kind of "flows" down the wiggling shape.

Imagine the top and bottom splines of the "ribbon' are "paths" to follow. If the "corners" or shape itself can follow the path you could just make the path wiggle and that shape would conform to it creating a pseudo "3d" effect.

That might be "possible" but it would require... a bunch of points assigned at specific distances along the spline. The distances would follow some kind of formula but I suppose it could be "tweaked" and done by eye.

Currently my script can only do one point at a specific spot based on the rotation of a bone. It would need to be expanded in some way so that any number of points would follow the same path at specified percentages along the path...

... this makes me a bit sleepy thinking about right now... haven't had my coffee yet.

-vern

slowtiger · Post by **slowtiger** » Wed Feb 04, 2009 6:48 pm

This is one of the cases where I can draw that ribbon frame by frame in just 10 minutes.

chucky · Post by **chucky** » Wed Feb 04, 2009 11:25 pm

Yeah you got it Vern , it was hard to describe that's why I used the word 'spine' so as not not confuse with other vector lines, unfortunately also known as 'splines'. I knew this was going to be Slippery.
Slow, you are absolutely right about the frame by frame thing, as you can see, that's how I illustrated the point, believe me though I have valid reasons for wanting an 'AS' solution, which I think would be also valuable for others.
Vern, I know exactly what you mean about the coffee, that's why got an extra big cup.

synthsin75 · Post by **synthsin75** » Thu Feb 05, 2009 12:04 am

http://www.mediafire.com/?kcmhly741my

Here's an ASified solution. Just point motion though, no real tricks. Maybe easier than tedious frame by frame though.

Took about five minutes to get it sorted out, but now that I know what needs to be done, it could be at least half that.

chucky · Post by **chucky** » Thu Feb 05, 2009 5:23 am

Wez you've outdone yourself and made it look easy.

I think you've done what I was struggling against by ignoring the extraneous issues that I was letting cloud my judgement.
I was always worried by what the ribbon or tail/tentacle or whatever, was joined to, which meant if the points travelled down the path I'd end up in trouble, but your short loop solves that, so I can make separate layers for each differently shaped wriggle, and switch,instead of worrying about building up clusters of points sitting on top of each other as spare points at each end of the extremity.
Thanks and well done, you busted my block.

heyvern · Post by **heyvern** » Thu Feb 05, 2009 5:34 am

Phew!

This means I don't have to jump on that script thing right away right?

p.s. I have a coffee mug almost that big. The local convenience store WAWA sold these 64 oz coffee "mugs". Holds an entire pot of coffee and has a handle just like a regular plastic travel mug.

I love to freak people out on the highway by drinking out of it while I drive.

-vern

synthsin75 · Post by **synthsin75** » Thu Feb 05, 2009 5:51 am

Thanks Chucky, glad it helped. I just can't seem to stand for anyone throwing down the gauntlet on AS. I'm more convinced every day that there is nothing AS can't do, and easier too.

My first attempt at this required some seriously stupid masking, so I can totally understand getting lost in some assumptions.

By all means Vern, take a break. You deserve it.

madrobot · Post by **madrobot** » Thu Feb 05, 2009 6:12 am

chucky wrote:]Thanks and well done, you busted my block.

Good to hear you cleared your blockage.
Don't want you hitting Melbourne's plumbing backed up to the neck.

Mikdog · Post by **Mikdog** » Sat Feb 07, 2009 10:26 am

Woah. Tricky one.

The way I would have tackled this is to first create one wavy point line and loop it. Make sure that looks good. Then duplicate it and bring it down to create the bottom wavy line. Then in another switch layer have the coloured joining parts as individual frames. Kind of tedious but I guess I wouldn't need more than 8 coloured frames, then they'd loop.