Force fields affect particles by attracting, repelling or accelerating them in some direction and can be used to model gravity, wind and other natural effects. Add force fields using the object browser, the main menu or alternatively, directly place a force field in the scene by right-clicking on the scene view while holding CTRL.
The following properties can be adjusted in the property panel to change the behavior of a force field.
|Lifetime||Time period during which the force field is active. If Repeat is selected, the force field always stays active and repeats its behavior.|
|Type||Type of the force field. |
Point forces attract or repel particles based on their distance to the force center. Particles near the center are influenced more than particles farther away. They have a circular area of effect.
Area forces accelerate particles in a specific direction if they move into the force area. In contrast to point forces, this direction is not towards or away from the force center, but set as a separate parameter.
|Size||Extent of the force field area.|
|Orientation||Orientation of the force field, in degrees. For 3D effects, the orientation is composed of roll, yaw and pitch.|
|Exclusion List||List of particle types not affected by the force field. Add and remove particle types via the context menu (right-click).|
|Position||Position of the force field. You can also specify a motion path along which the force field travels over its lifetime. It is shown in the scene view if the property is selected.|
|Direction||Direction in which particles are accelerated, in degrees. For 3D effects, the direction is composed of roll, yaw and pitch. Only applies to area force fields.|
|Strength||How strongly particles are affected by the force field. Negative values reverse the force direction. Point forces then repel particles, for example.|
|Grid||Number of cells used for the randomization grid. Each grid cell has a slightly different, randomly selected force direction and strength, which is influenced by the variance parameters for direction and strength. This is especially useful for more organic motion that moves particles with some variation in strength and direction. Click to randomize the strength and direction values of the grid cells.|