Animate opening a cylinder


I got some kind of cylinder (not exactly cylinder: the wrapping of a bottle, so a bit deformed on the top and bottom), and I’m trying to find out how to animate opening that wrapper a bit so you can see the bottle inside. The only tutorials I found go the opposite direction, and I can’t get that to work for me.

The wrapper doesn’t have to go to a complete plane, it just has to be “pushed aside” to show the bottle inside.


It would help if you at least showed a wireframe image of your model so we could figure out exactly what you mean. Ideally, put up a blend file. You say the tutorials go “the other way”, so what I’d suggest is using shape keys to control the deform and then animate the shapekeys.

Not sure if this is what your after and it by no means tidy, but may give you some ideas. Simple go to the vertex data panel and move the slider for the Key1 shape key. I bsaically did an edge split on the label wrapper, then maunally “unwrapped” it to expose the bottle underneath.

Kinda… Almost :slight_smile: One edge of the wrapper is to be attached to the bottle.

Here the wrapper that I have as blend file (I drew a simple bottle; cloned it; enlarged it slightly so it’s around of the bottle), and a photo of how it’s more or less supposed to unwrap. I used two pieces of paper to wrap the bottle in the photo; in the final design that’s supposed to be one big piecve. It doesn’t have to go straight but it has to bend away from the bottle. There’s a gap in the design; one vertical edge should remain in place (as hinge), the other edge is pushed to the side and the whole wrapper is straigtening a bit revealing the bottle.

wrapper.blend (482 KB)

I was looking at this:

But I have to go the opposite direction (and not deform the top/bottom like here to go to a sphere). Starting with the cylinder, than basically increasing the radius so it opens up. I don’t have to go to a complete flat surface, doubling the radius of the wrapped part is probably more be enough. Of course there will be some deformation in the top and bottom part which is unnatural but that doesn’t matter much, as long as it’s not too obvious :slight_smile:

The only thing you need to watch for with shape keys is that the ydo deform in a linear pattern, so I’m guessing you’d need another shape key as a “corrector”, unless someone with more experience of shape keys knows otherwise. :slight_smile: