Creates a field whose forces circulate around an axis.
- iOS 8.0+
- macOS 10.10+
- Mac Catalyst 13.0+
- tvOS 9.0+
- watchOS 3.0+
A physics field object. To use the field in a scene, attach it to the
physics property of an
The force on an object in a vortex field is tangential to the line from the object’s position to the field’s axis and proportional to the object’s mass. (The field’s axis is a line that is parallel to its
direction vector and that passes through its center. For details, see the
offset property.) For example, when a vortex field’s area of effect contains many objects, the resulting scene resembles a tornado: The objects simultaneously revolve around and fly away from the field’s center.
By default, a vortex circulates counterclockwise relative to its
direction vector. To make it circulate clockwise, set the field’s
strength property to a negative value.
falloff value for a vortex field is
0, indicating that the field’s effect is constant throughout its area of effect.