nxConstraints - Surface Tension

Overview Video

Surface tension happens when water comes into contact with the air.

The water particles are drawn together and the resulting fluid surface acts like a thin elastic sheet.

This is why water droplets bead and this is also what allows insects to balance on its surface.

The Surface Tension constraints layer simulates this phenomenon and is particularly useful when used in conjunction with an nxFluid modifier in PBD mode.

Weight

The Weight setting alters the influence each constraint type provides to the overall, global solution.

If you are only using one layer, this can be left at the default, 100%.

If you are combining different constraints in several layers, you could reduce this weight to lessen the effects of the connections and blend in other layers.

Connection Limit

A limit on the number of connections each particle can make.

Animation showing a decrease and and an increase in the Connection Limit amount during the simulation.

Radius

Particles will only be attracted to other particles within this radius value; increasing this will create bigger blobs of particles.

In this animation the Radius value is raised from 0 (zero) to 20 cm.

Inner

This setting negates the attraction force on particles.

This is used to prevent the particles from collapsing on one another when they get close to each other.

This animation shows the effect of reducing the Inner value, from 5cm to 1cm.

Tension

The strength of surface tension is given in this setting.

In order to get higher strength settings, you can increase the Iterations setting in the Object Properties.

Animation demonstrating raising the Tension value, from 0 (zero) to 100%.

Falloff

Set as Linear, by default, this is the falloff of the surface tension effect over the Radius distance.

The alternatives are: Flat, Cubic and Quadratic.