Liquid FX Modifier
Use this setting to select what the modifier does with the particles it affects:
- Enable: Standard particles are converted into Liquid FX particles with spray, foam, and bubble properties. The settings below define these properties.
- Set Properties: Changes the spray, foam, and bubble properties of particles that are already Liquid FX particles. The new values remain stored on the particles, even if they later switch to another type and therefore to another group.
- Disable: Converts Liquid FX particles back into standard particles. Note that standard particles do not have physical properties such as mass or collision detection by default and do not react to gravity automatically. If they are to continue moving, you may need to add these properties with other particle modifiers.
If this option is enabled, the converted particles receive the default radius that is defined for liquid particles in the simulation settings. They then have the same size as the liquid particles of the simulation. If the option is disabled, the particles keep their previous radius, e.g. the Radius defined on their emitter. The number of converted particles is not affected by this option.
Spray particles have only a few liquid particles as neighbors, for example drops that fly through the air. They simply move by inertia. As soon as they come close to the liquid again, they usually turn into foam. Note that newly converted particles are always classified as spray in the first frame, even if they are created inside the liquid.
Defines how quickly spray particles use up their lifetime. Higher values shorten the lifetime of these particles, lower values extend it. This value can only take effect if the particles have a limited lifetime, e.g. defined by the Lifetime settings of their emitter.
Foam particles float on the surface of the liquid. They are drifted by the surrounding liquid and stay at a specific offset from the surface. Foam is created, for example, when spray falls back onto the liquid or when bubbles reach the surface.
Defines how quickly foam particles use up their lifetime. Higher values shorten the lifetime of these particles, lower values extend it. This value can only take effect if the particles have a limited lifetime, e.g. defined by the Lifetime settings of their emitter.
Specifies how much the movement of the foam particles is influenced by the surrounding velocity of the liquid. At 100%, the foam follows the flow of the liquid surface. Lower values let the foam react less to the movement of the liquid.
Use this value to randomly vary the Drift per particle. The value can deviate from the Drift by up to the entered value.
Defines the distance between the foam particles and the liquid surface. The value is a multiplier of the average radius of the neighboring liquid particles at the surface, so at 100% the foam floats at a distance of roughly one particle radius. Higher values raise the foam as a whole. Note that this does not result in a thicker layer of foam, because the foam always remains coupled to the liquid surface.
Surface Offset Variance[-∞..+∞%]
Use this value to randomly vary the Surface Offset per particle. The value can deviate from the Surface Offset by up to the entered value.
Bubbles are located inside the liquid. They are drifted by the surrounding liquid and additionally experience buoyancy, so they rise to the surface. When they reach the surface, they turn into foam.
Defines how quickly bubbles use up their lifetime. Higher values shorten the lifetime of these particles, lower values extend it. This value can only take effect if the particles have a limited lifetime, e.g. defined by the Lifetime settings of their emitter.
Specifies how much the movement of the bubbles is influenced by the surrounding velocity of the liquid. At 100%, the bubbles are carried along by the flow of the liquid. Lower values let them react less to the movement of the liquid.
Use this value to randomly vary the Drift per particle. The value can deviate from the Drift by up to the entered value.
Defines the upward force that acts on the bubbles and simulates their buoyancy. Higher values let the bubbles rise faster, so they reach the surface sooner and turn into foam there.
Use this value to randomly vary the Buoyancy per particle. The value can deviate from the Buoyancy by up to the entered value.
These settings define how the Liquid FX particles behave when they collide with objects of the simulation.
Turns the collision detection of the Liquid FX particles on or off. If it is enabled, the particles react to static objects with a Collider tag as well as to objects that have received dynamic simulation properties, e.g. via a Rigid Body, Cloth or Rope tag. How the particles behave on contact is defined by the following settings. If the option is disabled, the particles pass through these objects without reacting to them.
Defines the friction applied to the Liquid FX particles during collisions, i.e. how much they are slowed down when they slide along a surface. As with liquid particles, the effect also depends on the Friction value of the colliding object, e.g. on its Collider tag.
Defines how strongly the Liquid FX particles stick to surfaces upon impact. As with liquid particles, the effect also depends on the Stickiness value of the colliding object, e.g. on its Collider tag. If one of the two values is 0, the particles cannot stick to the surface.
Defines the mass value of the Liquid FX particles that is used in collision interactions. Together with the speed of the particles, it determines the force the particles can exert on other dynamic simulation objects, such as rigid bodies or cloth.
Here you can link the Particle Groups in which the spray, foam, and bubble particles are managed after the conversion. When you create a Liquid FX Modifier, three groups are created automatically and linked here. By default, existing groups are reused if you create further Liquid FX Emitters or Liquid FX Modifiers.
Note that a particle does not keep its type permanently. It switches automatically between the three groups depending on the number of liquid particles surrounding it: A low number of neighbors turns it into spray, a high number into a bubble, and values in between into foam. The exact values for this can be set on the Liquid tab of the Simulation Scene object.
The Particle Group in which the spray particles are managed. Simply drag a different Particle Group from the Object Manager into this field or click on the pipette symbol next to the field and then on a Particle Group in the Object Manager.
The Particle Group in which the foam particles are managed. You can link a different group here in the same way as for the Spray Group.
The Particle Group in which the bubbles are managed. You can link a different group here in the same way as for the Spray Group.
Clicking this button creates three new Particle Groups for spray, foam, and bubbles and automatically links them to the fields above, even if other groups are already linked there. This allows you, for example, to manage the particles of several Liquid FX Modifiers in separate groups.