SPH - Display

RealFlow provides a wide variety of different settings to visualize specific properties of a fluid. The settings under “Display” can be edited for each emitter separately and give you interesting and valuable information about a fluid or even a particle’s attributes. Different colours can also be used to mimic a certain behaviour or fluid type, e.g. fire or dust.

Visible

You can choose between “Yes” and “No” to show or hide the emitter. Since the associated particles will also be hidden, this feature is perfectly suited if you want to monitor the motion of other nodes behind the fluid. You can also select multiple nodes and make them invisible in one pass.

Detail

You can choose between 5 different levels of detail to display the particle cloud: "Draft", "Low", "Medium", "High" and "Best".

Display type

You can choose whether you want to display the fluid particles as points or spheres. With “Sphere” you can already get an impression of what the meshed fluid cloud will look like. If you do not want to disable the viewport during a simulation (Alt + D) we recommend using the “Point” mode, because it takes some time to draw the shaded spheres.

Size

Here you can determine the radius of the points or spheres that are used to represent the fluid particles in the viewport. Values smaller than one are also allowed.

Show icon

Each emitter is represented by an icon in the viewport and you can enable/disable it here.

Show arrow

Each particle can be represented by an arrow indicating velocity and direction. The feature can be enabled with “Yes” and disabled with “No”. Since “Show arrow” visualizes the fluid’s vector field, programmers can use this feature for detecting misbehaving particles or exaggerated forces at certain points.

Arrow length

This setting assumes that “Show arrow” is set to “Yes” and defines the default length of an arrow.

Property

RealFlow calculates fluids on many physical data. With “Property” you can make some of them visible. The range of values for each property will be colour-coded with “Min range” and “Max range”. You can choose between a variety of attributes. By default, Vorticity is not computed during simulation and should be activated first under

Particles > Vorticity

Automatic range

“Yes” is the standard setting to create the colour gradient between “Min range” and “Max range”. The colours appropriate are shown in the “Min/Max range colour" fields.

Please do not forget that the values are not normalized and this can lead to flickering effects while playing back the simulation. To avoid this it is necessary to apply a normalizing script in a post process. Such a script analyses the entire particle sequence and limits the desired value to range between 0 and 1. This method is not only used in RealFlow, but also in other 3D applications to avoid shading problems because of huge differences, for example in velocity or pressure.

Min/Max range

Lets you manually adjust the minimum and maximum value for the selected property. Values below or above “Min and Max range” will be visually clipped and represented with the appropriate “Min/Max range color”. When a fluid’s attribute only has mean differences you will hardly see a colour range. With ranges you should aim for better visual differentiation.

Min/Max range color

You can select custom colours for the representation of the “Min and Max range” values. Clicking on the colour fields opens a browser from your operating system and you can choose any available colour from the RGB palette. This feature is often used to mimic certain fluid types, like oil, coffee, fire or similar.

Fluid

This setting requires some explanation and is related to grid-based fluids, specifically splash emitters: you might have already read that mist is created from splash particles. In this process, the splash particles’ radius is changed and some of the particles are most likely removed. This action changes the splash fluid and you will get different results. For that reason it is necessary to introduce a new concept, called “secondary fluids”. This subtype contains the modified splash particles, while the originally cached BIN sequence can be considered as primary. With “Fluid” you can visualize either the primary BIN sequence or the secondary modified particles. If you have more than one mist emitter attached, there is an appropriate number of “secondary” entries.

The standard setting here is “Primary” and, by default, this is the only option. “Fluid” is exclusively related to grid fluid mist particles. Mist can be calculated from previously simulated splashes, for example from a cached BIN sequence. Since splashes are also standard fluids, it does not make any difference whether you are using a “real” splash emitter or any other type.