SPH - RW_Object_Splash

The “Object Splash” emitter can be found under the “RealWave” node set:

Edit > Add > RealWave > Object Splash

From a technical point of view, this particle source is a standard particle fluid emitter, but it requires a RealWave surface. “Object Splash” cannot be used as a stand-alone emitter. When you work with this emitter type you will see that there are two RealWave-related panels. The reason is that you have to differentiate between the splash itself and the waves it creates on the RealWave panel. The first parameter set, “RW Particle Interaction” describes the behaviour of the RealWave surface when the splash particles hit the water. The second panel is “RW_Object_Splash” and here you can control the look and behaviour of the splashes around the object.

Objects

As usual you can choose one or even more objects from a node picker to attach them to the splash emitter. If you need control over the individual splashes then it is recommended to use one emitter per object.

Waterline mult

This setting is used to increase the number of created particles. It is closely related to he emitter’s “Resolution” parameter and ranges from 0 to 1. 0 disables the waterline emission, while 1 is used to maximize it.

@ Width

Experienced RealFlow users will certainly know that it used to be hard to create a sufficient amount of liquid-type particles around an object hitting a RealWave surface. Liquid-type particles can only be created at specific positions to keep the fluid stable. For better control, this parameter has been introduced. “@ Width” controls the area around the object from where the particles will be emitted. It works in world units – a value of 1.0 means that particles will be created in an area of 1 metre around the object.

@ H/V strength

These values can be seen as multipliers to enhance the splash. You can define values for the horizontal and the vertical emission separately. The range of these parameters is not limited and you can enter any value, but exaggerated settings should be avoided. Higher values will produce faster velocities in horizontal or vertical directions. A value of 0.0 for “@ H strength” may produce a perfect vertical emission, depending on the “@ V strength” value – and it is vice versa with 0.0 for “@ V strength”.

@ Side emission

This option modifies the angle and strength of the emitting particles along the normal direction. Higher values are required to create wide-angle particle emissions around the object.

@ Normal speed

With this parameter you can modify the speed of the particles when they are launched from the waterline.

Underwater mult

This setting works like “Waterline mult”, but the particles are emitted from polygons below the RealWave surface. This is great for creating particle trails from emerging objects or vehicles that move underwater, e.g. submarines. The range is between 0 and 1, where 0 disables the creation of particles.

@ Depth threshold

When you activate “Underwater mult” this setting becomes accessible. Particles are only created between the RealWave mesh and the specified “Depth threshold” value. “@ Depth threshold” must always be positive.

Speed mult

Another multiplier to influence the emitted particles. Each particle has a certain velocity at the time of creation. This speed will be multiplied with the entered valued to create more impressive, faster, and higher splashes. Very high values might lead to exploding particles and unnatural results, but with moderate changes it is possible to fine-tune a splash.

Parent Obj Speed

The object that is used to create the splash also has a certain velocity at the time of impact. A value of 0.0 will not add any velocity to the particles. A value of 1.0 will add the full velocity of the object.

Speed threshold

Particles will only be created when the speed of the object at that point is above the threshold. This option is useful to avoid particle creation at low velocities.

Speed variation

This is a random value that affects the velocity direction of all the particles being emitted.

Drying speed

The perturbing points of the attached object contain a wet/dry value that is updated when the object interacts with the water surface. When the point is below the water surface, it is considered “wet” and particle emission is allowed. “Drying speed” controls the transition speed from wet to dry when the object has come above the water surface. This is useful for creating the typical splashes of objects emerging from a water surface which continue to launch particles for a while. This is often observed with large objects, for example ships.