# Surface tension (no liquid inside objects)

I have an ocean project that is mostly finished but the main problem
is that when a bottle goes across the waves, the water is inside the bottle.
I read Cog’s tutorial in surface tension and actually did use that to make
some tension on the bottle, but I still don’t know how to make the water stay out of the
bottle. Cog mentioned something in December 2006 about using composite nodes to make it work but he never posted a tutorial.
Help is very much appreciated.

Are you doing this with fluid sim, with the bottle as an obstacle? If so, set the normals on the bottle to face out, and under the Obstacle settings, set Init Shell. The default is Init Volume, and liquid tends to leak through the mesh. You can also try subsurfing the mesh, increasing the number of vertices (subdivide) or increasing the resolution, though of course these all increase your calculation time.

Cheers

Clive

c’mon people… really, it’s not that hard…
use our support section for questions.
artwork section is for showing your work.

thanks,

.b

I am still hoping Cog will answer my question but he is super
busy right now.

Hi, here is how I would do it :
Make a small highly subdivided plane which will be used to create the ocean part around the bottle,and make a hole in the middle where you will put the bottle. You will delete some vertices in the large plane and put the small one will be joined to the large one used to create the whole ocean.
You can also subdivide a region of the original water mesh, instead of adding a small one to it.
Parent your bottle to 3 vertices (using Vertex Parent) around the hole in order to allow the bottle to follow the movement of the water.
It is better to have the center of the bottle mesh at the middle of the 3 vertices, to avoid the glass of the bottle crossing the hole limits.
I hope that this solution will fit your needs.
Philippe.

Hmm, I didn’t exactly get your technique. Thanks for posting though. =)

It is very simple : You dont want your water mesh to intersect the bottle mesh, so make a hole in your water mesh !
Then, link the bottle mesh to the water mesh using vertex parenting, in order to make the bottle follow the waves.

Ah, I see. I’ll have to try it out and see how it works.
I don’t need to do vertex parenting though because I already
hand-animated the bottle.