Creates a constraint that keeps a node within a certain distance of another node.
SDKs
- iOS 8.0+
- macOS 10.10+
- Mac Catalyst 13.0+
- tvOS 9.0+
- watchOS 3.0+
Framework
- Sprite
Kit
Declaration
Parameters
range
The range of allowed distances between the two nodes.
node
The target node used to calculate the distance.
Return Value
A new constraint.
Discussion
Distance constraints constrain a node to a specified distance range of another node or a point and can be used for effects such a simulating flocking around a node, repulsive fields and trails. Supplying a distance constraint with a range with a lower limit, an upper limit or both results in very different behaviors:
Example initialization | Behavior |
---|---|
| If |
| All constrained nodes are immediately attracted to |
| All constrained nodes are immediately attracted to |
Each time when constraints are applied, a line is projected between the node’s position and the target node’s position. The distance between the two points is calculated, and if it lies outside the specified range, the node is pushed or pulled along this line until it lies within the range.