Daemons - Attractor

The "Attractor" is also one of most commonly used daemons and perfectly suited to sculpt and shape fluids, enhance splashes, or create the famous “liquid dance” simulations, where particles are attracted and repulsed to create a dynamic and balanced movement. This daemon attracts particles towards its centre – negative values create a repulsion. Near the centre attraction forces become stronger and particles – or objects – experience greater acceleration. But not only fluids are affected by attractors, because this type can also act on rigid and soft bodies. Bodies with higher masses require higher “Internal force” settings. Another feature is that the "Attractor" daemon can adopt different shapes and its influence can be restricted with a bounding option. Animated "Attractors" are useable for many creative fluid sculpting approaches. 

Affect

Particles can be affected in two ways: either by “Force” or “Velocity”. The first option applies an external force, resulting in an acceleration, while the second one only modifies the velocities of the particles without introducing an additional acceleration.

Internal force

This value determines the strength of the attraction force. Rigid or soft bodies with very high masses, for example, normally need strong internal forces to start moving. Please note that this field also accepts negative values to create a repulsion effect.

Internal radius

If “Attenuated” is set to “Yes”, this option becomes editable. It is the radius where the attraction/repulsion force begins to attenuate. The parameter's unit is metres [m].

External force

Again an option which is only accessible with “Attenuated” set to “Yes”. It is the attractor’s strength in the outer area, defined by “External radius”.

External radius

The third value that is dependent on “Attenuated”. The setting determines the radius where the attenuation of the attraction/repulsion force ends. This radius is represented by a dark blue ring around the attractor and measured in metres [m].

Attenuated

You have the choice between “Yes” and “No”. “Yes” unlocks the previous three fields to specify the details for the force’s attenuation. “Yes” also tells the daemon that its attraction force declines with growing distance from the centre.

Attractor type

The daemon provides a total of three different attraction types: “Spherical”, “Axial”, and “Planetary”. “Spherical” is the default type and is represented by a point in the centre of the daemon. “Axial” produces a force field along a line from up to down – this line is also shown in the viewport. If you want to change the direction of the axis you have to rotate the daemon, using the appropriate "Node" settings. “Planetary” is represented by a sphere around the daemon’s centre. Within this sphere there is a linear force field. It simulates a planet’s force of attraction which extends from the planet’s centre to outer space. The planet’s radius is controlled with the following parameter.

Planet radius

Control the radius, given in metres [m], of the virtual planet here. This option is only available with “Attractor” type set to “Planetary”. The daemon’s viewport symbol will be updated automatically to indicate the new radius.

Axial strength

This is the vortex strength in the axial direction. It can only be used with the “Axial” attractor type.

Bounded

Here you can determine whether the attractor’s forces are bounded or not, and the two possible settings are “Yes” and “No”. To change the dimensions of the boundary, it is necessary to enter new scale values in the "Node" panel. The values for X, Y and Z can be controlled independently, and it is also possible to create elliptical boundaries. The bounding sphere is displayed in the viewport as three circles.

The daemon's bounding sphere can be distorted with the “Shear” parameter under “Node”, but this only affects the visual representation in the viewport. The daemon's scope is not affected.