ProbeNode

ProbeNode (from scenerystack/scenery-phet) draws a stylized, beveled sensor probe: a circular sensing head with a handle at the bottom, shaded with gradients to look physical. It was generalized out of Bending Light and Beer's Law Lab, where it's dragged around a scene and connected by a WireNode to a body that displays the reading. ProbeNode itself has no Property or reading logic — it's pure graphics, plus a slot (sensorTypeFunction) for what's drawn inside the circular sensor area.

import { ProbeNode } from 'scenerystack/scenery-phet';

A minimal example

const probeNode = new ProbeNode( {
  radius: 50,
  innerRadius: 35,
  sensorTypeFunction: ProbeNode.crosshairs( { intersectionRadius: 6 } ),
  cursor: 'pointer'
} );

The origin of a ProbeNode is the center of its circular sensor area, not its top-left bounding-box corner — useful to remember when positioning it against a model coordinate.

Constructor

new ProbeNode( providedOptions?: ProbeNodeOptions )

There are no required positional arguments — everything, including size, is an option.

Options

Option	Default	Effect
radius	50	Outer radius of the circular sensor head
innerRadius	35	Radius of the cut-out sensor area inside the head (clamped to <= radius)
handleWidth	50	Width of the handle at the bottom
handleHeight	30	Height of the handle
handleCornerRadius	10	Corner radius of the handle
lightAngle	1.35 * Math.PI	Angle (radians) the simulated light comes from, used to place the gradient highlight; 0 is from the right, PI/2 from the bottom — since scenery's y-axis points down, increasing angle rotates clockwise on screen (right → bottom → left → top)
color	'#008541' (dark green)	Base color of the probe body; all gradient shades are derived from it
sensorTypeFunction	ProbeNode.glass()	A (radius) => Node factory that produces what's drawn inside the sensor cut-out; pass null to leave it empty

Static factories for sensorTypeFunction

Static member	Produces
ProbeNode.glass( { centerColor, middleColor, edgeColor } )	A radial-gradient "glass lens" look (the default)
ProbeNode.crosshairs( { stroke, lineWidth, intersectionRadius } )	A crosshairs pattern, with a gap at the center
ProbeNode.DEFAULT_PROBE_NODE_OPTIONS	The full set of default option values, useful for combineOptions when writing a custom sensorTypeFunction

lightAngle is not auto-derived from the Node's rotation

Because ProbeNode can't reliably know its own global rotation within a scene graph, lightAngle must be set explicitly by whoever places it — it does not update automatically if you rotate the probe. PhET's convention is a light source from the upper-left, so rotate lightAngle to match however you've oriented this particular probe.