setup( builder ) {

		// irradianceLightMap property is used in the indirectDiffuse() method of BasicLightingModel

		const RECIPROCAL_PI = float( 1 / Math.PI );

		builder.context.irradianceLightMap = this.lightMapNode.mul( RECIPROCAL_PI );

	}
The light map node.

@type {?Node<vec3>}