Thread Unwinds Forming Shape?

[Atom]

Hi All,

I am trying to implement a concept of a spool of thread that unwinds leaving a trail that then takes on the shape of the classic "support this cause" ribbon.

I have started with Matt's Pop Trails example file and replaced the scatter with an Object Merge of a single point from an external object that tracks the spools Z position. This gets me a single thread trailing the spool.

What I don't know how to do, is to make the trailing thread take on the proposed shape for the concept?

Is this Pop Trails example the best way to handle this or is there a better approach?

 

Thanks

ap_me_pop_trails_spool_thread.hipnc

Edited June 17, 2016 by Atom

[michael]

you could unroll your thread to the point where you want to spool to stop moving, then take the unrolled curve and cut off a copy at a specific length - then shape that into the ribbon

now you have an unrolling curve and a ribbon curve with the same point count - now you can use a wrangle or just a point SOP to move the unrolled curve into the position of the ribbon curve.

[Atom]

I setup something similar to your suggestion. I have a separate geo that references the points after the DOPs simulation. Then I take the source of the ribbon geometry and resample it to the same count as the DOPs count. Then I can use a BlendShape to morph between the two shapes.

There are a couple of problems with this. I have manually set the point count so I am not sure exactly how to read the point count from DOPs and set the resample node to that value on-the-fly.

Also I need a way to keep the ends of the string from fully adopting the ribbon shape. The ribbon needs to appear within the length of the string so the end remains dangling and the start still remains attached to the spool.

I guess I need some kind of fall off group that spans the length of the DOPs count then only uses that point count for the resample...

 

I was also playing around with the differential growth example to see if I could change it to morph into my ribbon, no luck yet.

ap_me_pop_trails_spool_thread.hipnc

[bandini]

For the part forming into a ribbon, I would probably use a path deformer (you could make simple one with wire capture or download one of the ones from orbolt). Create a curve, rig your cv's to nulls to use as control points, and then manually deform into place. You can easily control how the ribbon forms that way. can also post-process the control points in chops to get some flowing motion. A few SOPS tricks can transfer the motion of your path deformed path to your particle generated path.

[mestela]

Yeah, I don't think sim is the way to go here, its a bit too uncontrollable. Had a go anyway, the curve force sorta works, but I suspect would get nasty if you needed to hit specific shapes or timings.

Also got a wire example in there too, again, sort of works, but probably not ideal.

thread_curve_force.hipnc

[Atom]

Thanks for the suggestions. The popcurveforce might work because i don't have to form words, AFAIK, just simple shapes.

I have a revised version of the scene with an attempt to integrate the popcurveforce Matt's file demonstrates, but it does not seem to have any effect in my scene. I want the particles in the blue range to be attracted towards the shape.

ap_me_pop_trails_spool_thread_1e.hipnc

[Atom]

After playing around with this some more I think blendshapes might be the easiest way to animate this. I could have a switch at the top of the target curve stack for animating which shape would appear within the line. Then just animate the blend weight to reveal the shape. Particle life is the maximum length of the line.

The problem I am having is that the entire particle line takes on the form of the target shape curve. The end points of the line need to remain where they are during the animation. I'd like to find a way to only use a percentage of the line for the blendshape. So the shape could appear in the middle of the line.

I am not really sure how to feather a blendshape or add fall of with locked ends?

ap_me_pop_trails_spool_thread_1e.hipnc