Samples all of the field nodes in the scene and returns the summation of their forces at that point.
- iOS 8.0+
- macOS 10.10+
- tvOS 9.0+
- watchOS 2.0+
A position in scene coordinates.
The summation of forces exerted on that point.
The sample is calculated as if a physics body is placed at that position in the scene. The body is assumed to have a mass of
1, with no charge or velocity. The body is affected by all field nodes.