Cineversity

Hello:

I’m working on an animation that shows the inner workings of an inkjet cartridge.  The process involves a bubble expanding within a chamber and pushing out past some posts.  The bubble deforms around the posts. 

This image shows the gist:

http://marshall-arts.net/test/MicroBubblepostsRef.png

I’m been using a Spline Rail deformer to create the flare out at the end.

I’ve been working to create the basis of an effect like this using the collision deformer, but the results have been unsatisfactory.  I’ve spent several hours trying different combinations of mesh density and advanced collision settings, but I end up with two basic results.  If I keep the stretch value low the bubble will push around the posts, but the top collapses down and pushes through the bottom of the mesh.  If I crank up the stretch that collapse is mitigated, but the bubble barely pushes past the posts.

I’ve attached the scene file I’ve been using to experiment. 

I’m open to trying another deformer, but I’m not sure what would create a comparable effect.  I thought maybe using a bulge deformer with a falloff could work, in which the bubble pushes out and gets indented when it hits the deformer, but while the bulge deformer will indent the bubble it also pushes the top up and the bottom down.  I really wish there was a way to make the bulge and other deformers work on a single axis.

Any thoughts?

Thanks.

Shawn Marshall
Marshall Arts Motion Graphics

Hi Shawn Marschall,

Have a look to the short adjustments that I did to the file. Main change: mesh-springs all to lower, and “Outside (Volume)”.

Is that closer to the way you would like have it? It should get “thicker” close to the impact areas… Perhaps it is easier to animate that with PoseMorph. It is not really volume-perservetative.

Yes it is always a very specific mix.

All the best

P.S.: Certainly more work, but I think that comes closer…
The Cylinder for the visual should be larger, and the ones for dynamic collision invisible.
With more “Plain Effectors” you might get even a more realistic result. (Movie is attached)
BTW, I used the Subdivided Smooth Subdivision.

:o)

Thanks for taking the time to work on this; I appreciate your effort.

I don’t know whether this collision deformer approach will give me the results I need.  It’s a shame because it feels like it should do the trick.  I’m going to play around with using the Inside (Stretch) functionality of the Collision Deformer.  Maybe having three objects inside the bubble pushing out those fingers will work.

I also didn’t know that Effectors could be used as deformers on normal geometry.  Has that always been the case?  By playing with the orientation of the plain effectors you added to the scene I can sort of get a good indentation.

Cheers.

Shawn

Hi Shawn,

I think an intensive study of the “maps” is perhaps needed, to reproduce what you like to have. In this way you can choreograph the “damage”. Without that, so it seems, the polygonal forces have the same amount, and the ones where the impact happens, might experience the problem to move, but the same “power” is given to the surrounding polygons. So the impact-energy is not really relieved to the context, roughly said. This is normally done with specialized “crash applications” were the force/power working on the parts can be defined, as every edge or bend even change the “resistance”. But, for impact oriented calculations, the dynamic/inertia is a critical part in the equations. Any accelerated object receives an inertia to the power of two, which means the time is a very critical element here. It is, as far as I know, not implemented in C4D, for a good reason! What you ask for is specialized and highly computational expensive. As we talk here about visualization, we need more often than not do some support to get the wanted result. These results vary, and realistic is perhaps the smallest amount of request here. In VFX things follow to support first and mostly the story, not always so much the given reality. As a visual artist, I don’t care about reality, I care about visual impact. Perhaps that explains why the options are there to adjust this manually and follows more your vision with it, than setting up material parameter, dynamics and inertia, etc.
=====

If my memory is not playing games with me, the option to be used as Deformer is there from the beginning, nine years ago. Note that the Effector Parameter>Transform Mode and Space is critical here.

My best wishes

Hi:

I ended up getting a usable solution to this using the correction deformer.  The attached file shows the setup.  The spline rail deformer restricts the basic bubble model inside a chamber, with one correction deformer helping to push the bubble around the posts and another to pull the bubble down into a nozzle hole.  Though the bubble is still intersecting the posts somewhat you won’t be able to tell from the angles we plan to use.  I just needed it to look like the posts were impeding the progress of the bubble somewhat.

Thanks.

Shawn

Nicely done, thanks for sharing, Shawn.

I like the combination of options, and it follows more my own philosophy: to have the most control. :o)

My best wishes for the project

Sassi