The URL for a file that contains photometry data describing the intended appearance of the light.
- iOS 10.0+
- macOS 10.12+
- Mac Catalyst 13.0+
- tvOS 10.0+
- watchOS 3.0+
A photometric light source is one whose shape, direction, and intensity of illumination is determined by a file in the IES format, containing physical measurements of a light source. Many manufacturers of real-world light fixtures publish such files describing the lighting characteristics of their products. This photometry data measures the light web surrounding a light source—measurements of the light’s intensity in all directions around the source.
By default, this property’s value is
nil. After setting this property to a URL that references a valid IES profile, you must set the light’s type property to
IES to load that file and apply its effect.