Hi, I’ve been tasked with animating what is essentially a tire mold. How the mold works is that a round piece of rubber (that will become the tire) is placed over a rubber bag (shown in attached image). The bag inflates and pushes the rubber into a mold.
In one animation they want the rubber bag to inflate. In another, they want it to deflate, but then get sucked into a small hole in the bottom of the machine.
I tried tossing a squash and stretch deformer onto it, which kind of works, as it bulges out, simulating some inflation. However, I think they’re going to want something a bit more custom. Maybe I should try the Pose Morph tag? Just not sure how I would get it to suck into the a small hole in the bottom.
Would this even be possible to do an actual cloth simulation? Just trying to see what’s possible here.
A while ago I had sent you an upload link, would you mind using it for the image and the scene file. The Forum’s software obviously corrupts the file at the moment. Sorry about that, I hope it is fixed soon.
(From what I know about tire production (Having been in my younger years a mechanic on motorcycle races [europe/world champion ship]. So tires were a theme of course.)
Ballon like… A tire production doesn’t work that way. There are a few layers, besides the rubber, a steel-fabric and several other parts, all of them won’t expand at all. The Green-Tire is a construct of all those parts before it becomes vulcanized, and with that imprinted with the pattern.
This is a process that uses heat and steam as well the mold like a “steam-punk-waffle-iron”. If one could inflate a tired that easy, you would bring it out of shape with any little change of tire pressure. Which would be catastrophic, of course. However, are we talking about tires or something else? I guess that was just an example.
Think from the final shaped product, then smooth a copy (Iron, Smooth Deformer) without changing the mesh (amount of points, polygons, nor their order), Use a PoseMorph to blend. Additionally, a Sphere deformer might help.
Thanks Dr. Sassi, and it’s great that you actually have an idea how this works!
I didn’t think of using the sphere deformer, that’s a great idea too.
In this instance, the tire itself isn’t what I am animating. But instead the “bladder”. It’s like a rubber balloon that presses the rubber into the mold. Is there a way to “suck” the rubber balloon into a small hole? As if it’s warping? Apparently on these units, that rubber bag (bladder) pops and the pressure forces it out of the press.
Oh oops, what I sent you is basically the start. They provided a CAD file of this, and I remodeled it so that it could be animated. If it helps, I could provide the mold that it would fill as well?
I have shaped splines in three versions: the start, the inflated, and the final shape. Whereby the start shape has a more flat and a more curved mix.
Anyway, to create any shape you like, without getting mad about the point amount, I used the MoSpline to translate each spline into a spline with the exact same point number. Current State to Object and you get a unified piece delivered.
This works then excellent in the PoseMorph, set to points. Note that I use the middle state as a starting point, so I avoid mixing poses.
The start shape would work with a Lathe, so I had to set up two profile Pose Morphs. With the Loft, such a shape is doable. Mine here is more to demo the workflow.
Deformers can be used of course, to get more flow into the set up.
Thanks for the feedback, Matt,
I hope the two ideas or a combination of it will give you the animation you are after.
When I think about inflating an object, of course,, Softbodies comes to my mind. However, the polygons will give the “resolution” of how much they can get into the shape of the mold. Hence why I think that going from the end product to the more soft and roundish shape is the better way. It is easier to flatten than to fit into a given form (as in edge lines up with a given edge).
The Spline idea works perhaps here as well, as the mold had not the tire profiles, and an initial Spline can be animated with PLA as well. Or just with the PoseMorph Deformer?
Since I’m mostly interested in the delivery of content, the rendering, the video or film, there could also be a mix later in the edit. I’m aware that you think about these options, but I write in a forum, so I wanted to point to that obvious “do it in post” tip as well.
If there is a problem or question, or the wish to look for something completely different to pull it off, please let me know. I’m happy to look into it.
Thanks again Dr! Yes, I’m hoping they don’t want something more detailed, as the CAD file they provided didn’t have the “tire tread” built into the mold.
I think this idea will work great for what I am doing though. I sure appreciate your help here!
Even if they need a profile in some areas, it could be done with an object that sits at one point inside the Rubber-Balloon. Introduced perhaps with a Bump-map, to have a nice introduction.
Oh these are very helpful! I especially liked the last example with the cloth. I think this might just be the ticket to what I’m after actually! Thanks again, this is very helpful!
This sounds great, I’m happy that you see use in those setups.
Going by your last project that we have discussed here, I know that film-editing is part of your visual thinking. Since I write in a forum, I like to point out that all these different ways might work nicely for one “take” and after a cut, another function is used.
Let me know if there is something else, as usual, I’m happy to look into it.
This setup is basically with the mold closed. I tried animating the size parameter as you did, but the cloth does not stay within the mold. You’ll see that it kind of goes all over the place. Do you think it’s even possible to have it fill the space properly?
Then the reverse, I am trying to get it to suck in around the Airflow Hole. But I can get to that point after the first part of having it expand the mold.
As pointed out above, I don’t see that really as an option, as edges and points need to match. Don’t get me wrong, all these parts that create a dynamic effect are priceless. However, to just have it done all the work in one step, and as precise as one might like it, I don’t see that. At least the endpoint might require a defined static model, morphed, while an excellent detailed model is targeted.
Yes, that is tricky, to pin a lot of points down, and have intersecting polygons. I tried with Weight Tags and Field combinations to art direct the Cloth as well some trial and errors with SoftBody.
As usual, I’m never really convinced and pulling a parameter for one part, messes up the next stage. My intention was more to have that short moment when it goes into the machine, to have that like a rubber aesthetic while it gets pressured inside. As mentioned, I do not see that it will go close to the mold. I tried two hours, just to be confident, and yet, perhaps a magical sweet spot of all parameters might make it work. If efficiency is the target, I stick mostly with old school animation and use dynamics as aid, not as the primary tool.
The suggestion that I would give, use Cloth or SoftBodies to get poses, and use those (Current State to Object) then in a PoseMorph. There is nearly no better way to fine-tune the results for animations like this. Anyway, as hinted, any cut to detail can be purely dynamic based. To find the right balance and mix is the key.
In the file, I have used different techniques to get these intermediate shapes, and I started with a copy of the Mold, scaled to the starting point. I guess the shape would go first into a more balloon shape, then again into a cylindrical. Restrictions to its collar (in your model) perhaps.
