View Full Version : Unfolding around an exis, like an opening fan

11-18-2017, 08:27 AM
I'm getting lost in my experimenting!

I need to unwind geometry around an axis, in a very similar way to how a paper fan unfolds. So I start with a narrow wedge, and stretch it out around the apex, (or the other way round), until it's a ful circle.

It's actually for unfolding a solar array, as seen in this short video.

Best I can come up with so far is to model about 1/8th at a time and use morph targets, but even there I'm getting confused with tools and options regarding which tool will make the required transformations in modeller.

Anyone got any ideas for an elegant way to handle this?
And what's the modeller tool for this kind of radial stretch?

All clues gratefully received...

11-18-2017, 11:15 AM
I woundn't do it in modeller. Use Bullet or FabricFX to do one panel, then when its right, save as FBX and clone it appropriately. Set-up would be simple with a few nodes.

11-18-2017, 03:36 PM
Are you simulating opening the panel in the assembly room, or in space? I'd think that if it's being deployed in space, most of the jiggling and flopping that the solar-cell cloth-like material does wouldn't happen and the simulation would be much easier.

Most of the jiggling and flopping in the video is because each rib is suspended from a circular track in the ceiling, and clearly the runners / rollers up there get caught up, the video is paused while they're unjammed and then the opening continues. In space, it would probably be quite smooth with only a little flutter of the material, if any. In that case, I'd think the morph method would work fine, perhaps using an enveloped Turbulence procedure to make the material flutter a little until it's tight.


11-18-2017, 06:08 PM
should be possible according to Bryphi...


11-18-2017, 06:38 PM
i have a video on my hard-drive showing a node setup, looks to be gone from the web?

pie chart video, goes like this >
-create a lathe. make sure "U" is ticked. this will create a UV map
-use "UV to weightmap" tool
-use rotate tool with "weightmap" falloff. "un-rotate" the lathe.
-in short(!) hook >weightmap into >gradient into >rotate into >displacement.

if problematic, i can send you a PM-link of the video.

11-18-2017, 10:17 PM

Not the prettiest way to go about it...

11-19-2017, 04:44 AM

Not the prettiest way to go about it...

That's what I am after, as someone else observed, jiggling not important!

(And thanks to others too)

11-19-2017, 07:44 AM
might be of use...


11-19-2017, 10:48 AM
Here's my rough as nails attempt using Instances. Of course, it assumes they don't connect together:


11-19-2017, 10:53 AM
Awesome!  :king:

11-19-2017, 11:48 AM
The radial instance array with a morphed base object seems like a really good approach. As long as you can accept the separate sections of the panel unfolding simultaneously, since Time Offset in Instancer doesn't work with morphs / displacement of the base object.

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