Daemons - Display Force Field

Owned by thomas (Unlicensed)
Last updated: 04 Jun, 2014
3 min read

In the past it has been difficult to evaluate direction and strength of daemon's force. With RealFlow's “Mist” domain node users had the ability to make the forces visible, but the workflow was not really established and required an additional node. The “Display Force Field” panel provides a quick and fully customizable method to visualize the force field.

A visible force field gives you a better idea of how a daemon acts on a fluid or an object, and you can visually “debug” the force field. With visible forces you are also able to understand the influence of specific settings on how they change field, because all settings will affect the viewport's representation in realtime; a good example are different attenuation methods or falloffs.

Please bear in mind that only position-based force daemons offer this feature. Excluded daemons are: 

  • All “k” daemons

  • “Color Plane”, “Heater”, “Texture Gizmo”, “Filter”, “Sheeter”

  • “Coriolis”, “Ellipsoid Force”, “Drag Force”, “Surface Tension”

  • Plugin daemons and scripted daemons

The reason, daemons like “Coriolis” or “Ellipsoid Force” are excluded is that they depend on a fluid's or object's velocity and this property is not known before the simulation starts. Therefore, the field cannot be displayed.

 

Show field

By default, this option is disabled. When you change it to “Yes” you will see a box of 10 m x 10 m x 10 m in the viewport. At first glance, the box's content could look a little “chaotic”, but with the different “@” settings you will be able to bring order into the force field's representation. The forces themselves are displayed as arrows of varying length and orientation. The length is a direct measure for the daemon's force strength at a specific point in space. The arrowhead points in the force vector's direction.

All transformations, performed on the daemons, will affect the field's box immediately. This does not only affect scale changes, but also position and rotation changes.

Interesting effects can be achieved when you move or animate the daemon's position through the field box.

@ spacing

This parameter value is measured in metres [m] and defines the distance between the arrows in the field box. A value of 0.5, for example, means that you will see one arrow each 0.5 metres. With lower settings you will get more arrows and a “denser” representation of the field.

@ magnitude scale

With this parameter it is possible to change the length of the arrows (= magnitude). Please note that the arrowheads will also be scaled. With high values, the field's viewport representation might become confusing. In this case we recommend increasing “@ spacing” and/or decreasing “@ magnitude scale”. The value works like a factor: 2.0 will double an arrow's length.

@ position

Please do not mix up this value with the daemon's physical position in space. “@ position” only describes the position of the field box. Simply enter values for the X, Y, and Z coordinates to get a view of a different area of the field. The values are given in metres [m].

@ scale

If you want to adjust the box's size please enter values for the X, Y, and Z coordinates. The values are given in metres [m].

EDIT field box

Another alternative to the “@ position” and “@ scale” parameters is to press this button and use RealFlow's “Move” and “Scale” tools. Rotation is not supported. Please do not try to scale the box with parameters under “Nodes”, because in this case you will transform the daemon's bounding box, not the field's box. Once you are happy with the transformations click on this button again to prevent the box from unwanted changes.