“Circle” is an area emitter. Emitters define the point of particle creation in 3D space, while the particles are part of the "Fluid" container. Emitters can be scaled, rotated, and translated like objects; an arrow indicates the direction of emission.
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To learn more about how to link RealFlow scene elements and make them interact take a look at the → "LinksManual Linking" page with examples.
Emitter Type
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This feature creates a defined volume of particles. The size of this volume is defined by the emission area and the value entered here. Another way of creating a volume is to go the emitter's viewport gizmo and drag the middle handle up and down. This action will change the volume interactively and update the parameter accordingly.
Speed
Here the particles' initial speed is defined in metres per second. Higher values will generate more particles per frame. The number of emitted particles also depends on the fluid's “Resolution” settings. A value of 0.0 stops the emission of particles.
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