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By default, particles are created inside the volume of the attached object and then released. With this parameter it is possible to switch on a continuous particle stream, similar to RealFlow’s standard emitters. To make the emitter create particles with “Stream” turned on, “Initial speed” can even be 0.0. In such a case, the particles’ velocity is a result of the scene’s daemon forces.
Initial
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@ speed
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velocity
With “None”, the fluid's initial velocity is 0. With "Constant" the "@ speed" parameter is unlocked so you can type the initial speed of the fluid. The direction will be represented by the emitter's arrow in the viewport. With “Inherit” it uses the velocity of the attached emitter object – this is
interesting for animated emitter objects. With both "Constant" and "Inherit" the parameters to randomize the initial velocity will become accessible.
@ speed
Here you can adjust the particles' velocity at emission time in metres per second [m/s]. The direction of the initial velocity can be controlled by simply rotating the emitter node in the viewport. An arrow in the centre of the emitter’s symbol indicates the direction.
@ angle variation
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@ speed variation
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Surface particle sampling
The Hybrido fluid's surface plays a very important role with Hybrido simulations, because it is responsible for the creation of the secondary effects as well as the quality of the mesh. The particles inside the cells also contribute to these features. With this parameter it is possible to adjust the number of surface particles within the given "Surface bandwidth" – independent from the main body of fluid. . This parameter is only accessible when “Initial velocity” is set to “Constant”.
@ angle variation
This parameter is used to create more randomness and is measured in degrees [deg]. This parameter is only available with “Initial velocity” set to “Constant” or “Inherit”.
If you are interested in the technical background please continue reading: When the particles leave the emitter they have an initial velocity vector. When you define an angle variation, an angle is created around this vector, so it forms a so-called solid angle which looks like a cone. The final, randomized velocity vector will be inside this conical volume.
@ speed variation
The particles' initial speed can also be modified to avoid a uniform look and add more randomness. The variation is given in metres per second [m/s] and will be combined with the value from “@ speed” or the attached object's inherited velocity. This parameter is only available with “Initial velocity” set to “Constant” or “Inherit”.
Surface particle sampling
Here you can adjust the number of particles per cell for the fluid's surface The total number of particles per cell is calculated with the following formula:
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Analogue to “Surface particle sampling” the main fluid body can be adjusted as well. With this parameter you determine the number of particles of a cell outside the “Surface bandwidth”. These particles are considered "core" particlesin the fluid's core are. The formula is exactly the same as above:
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