LightRaysNode

LightRaysNode (from scenerystack/scenery-phet) draws a fan of straight line segments radiating outward from a circle of a given radius, filling roughly three-quarters of the surrounding circle. It's the "glow" effect behind LightBulbNode — which constructs one internally — but it's a standalone Path you can attach to any circular light source (a laser aperture, a glowing indicator, etc.) and drive directly.

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

A minimal example

const bulbRadius = 20;

const raysNode = new LightRaysNode( bulbRadius, {
  stroke: 'yellow',
  maxRays: 40,
  maxRayLength: 150
} );

raysNode.setBrightness( 0.75 ); // 0 (no rays, invisible) to 1 (maxRays, full length)

Constructor

new LightRaysNode( bulbRadius: number, providedOptions?: LightRaysNodeOptions )

bulbRadius is the radius of the circle the rays emanate from (they start at that radius, not at the origin).

Options

Option	Default	Effect
minRays / maxRays	8 / 60	Number of rays at brightness 0 (rays only appear above brightness 0) and brightness 1
minRayLength / maxRayLength	0 / 200	Ray length at the low and high ends of the brightness range
shortRayLineWidth / mediumRayLineWidth / longRayLineWidth	0.5 / 1 / 1.5	Stroke widths interpolated across as computed ray length grows
stroke (inherited PathOptions)	'yellow'	Color of the rays

Methods

Method	Effect
setBrightness( brightness )	Recomputes the number, length, and line width of rays for a brightness in [0, 1], and sets visible = false when brightness is exactly 0

At brightness 0, the shape becomes an invisible circle, not an empty shape

When numberOfRays drops to 0, LightRaysNode still assigns an (invisible, since visible is set to false) circle of radius bulbRadius as its shape rather than clearing it entirely — this keeps local bounds well-defined at construction time instead of momentarily reporting empty bounds.