SPH - RW Particle Interaction

Here you adjust the particles’ behaviour when they interact with the RealWave surface. "RW Particle Interaction" is also responsible for secondary waves created by a particle’s force. Whenever you are working with splash or crest particles, you should pay special attention to this panel, because it greatly enhances a simulation’s credibility.

Upward force

Particles below the water surface always try to move in the direction of the surface and counteract gravity. This tendency can be adjusted with “Upward force”.

Destroy on depth

Particles that reach the entered depth will be deleted and removed from the scene. This value strongly depends on the wave modifier you use and the final wave height.

On surface

You can choose from three options: “No interact”, “Destroy” and “Place”. “No interact” makes the particle fall through the RealWave surface – there they can be deleted with a "k Volume" daemon, for example. “Destroy” automatically removes the particles when they hit the surface, and with “Place” they float on the surface. With “Place”, particles might accumulate between the wave crests and should be deleted with a "k Age" daemon.

@ Friction

This parameter is only available when "On surface" is set to "Place". You can adjust the particles' friction to make them stay closer to the object for a longer time.

Split

“Split” will break the particles apart to create child particles. Once it is set to “Yes”, you will have access to “@ # child”. “Split” can create huge amounts of spray, foam and splash particles, so please mind your “Max particles” settings.

@ # child

Here you can determine the number of children that will be generated from each particle when “Split” is set to “Yes”.

Hit force

Each particle has a certain mass that is capable of influencing the RealWave surface. This mass generates a force that creates little ripples and secondary waves. If you need stronger ripples, you do not have to change the fluid’s density (which would lead to a completely different fluid behaviour); simply raise “Hit force” and boost this effect. Depending on size, level of detail and environmental conditions, it is sometimes better to deactivate “Hit force”. Large “Hit force” settings in combination with high “@ Wave speed” values can lead to unwanted high-frequency patterns.

Hit levels

With values larger than 0, RealFlow analyses the neighbour of the affected vertices of the RealWave surface and disturbs these points. This mode can be seen as a "radius of action", and it is a recursive operation. With a value of 2, for example, the neighbours of the already considered vertices will be disturbed as well. This means that high values will A) slow down the simulation and B) affect very large parts of the wave surface leading to an unnatural look. Therefore "Hit levels" should not be greater than 5.

@ Max height

Since particles can create ripples and secondary waves, it is sometimes necessary to restrict the height of these waves to avoid unrealistic behaviour. Imagine an ocean surface where tiny drops produce huge waves. That is an example where relations are shifted and the effect is completely overdone.

@ Wave speed

The travelling speed of the secondary ripples can be restricted with this parameter. High velocities can also lead to unwanted spikes and high-frequency effects which spoil the entire wave.

@ Wave damping

To prevent the particle-induced waves from endless propagation, we recommend to limit their life-span. With “@ Wave damping” you can make them disappear smoothly and create a much more realistic behaviour.

@ Depth effect

An object can disturb the surface and create waves not only when it crosses the surface, but also below it. As in real life, a submarine can create waves when travelling below the surface at a shallow depth. This parameter sets the depth limit at which any object will affect the surface.

Texture strength

If you can hardly see the particle marks on a foam texture, we advise you to either raise this value and/or the emitter’s “Resolution” parameter. To achieve a less distinctive effect, values smaller than 1 should be considered.