Instance Property


The minimum exposure value to use in tone mapping.


@property(nonatomic) CGFloat minimumExposure;


When using a High Dynamic Range (HDR) camera, SceneKit applies a process called tone mapping to translate the wide range of luminance values in the visible scene to the narrower range of brightness values that can be shown on a display. SceneKit determines a tone mapping curve from the minimumExposure, maximumExposure, exposureOffset, and whitePoint properties, along with a measure of scene luminance.

Exposure values are exponential: a value of 1.0 doubles brightness, a value of 2.0 quadruples brightness, a value of -1.0 halves brightness, and so on. The default value is -15.0. Increasing the value causes darker portions of the scene to become under-exposed (uniformly black, losing definition). Decreasing the value adds more dynamic range for darker portions of the scene; however, a greater breadth of difference between the minimum and maximum exposures decreases contrast.

This property has no effect if the wantsHDR value is NO.

See Also

Adding High Dynamic Range Effects


A Boolean value that determines whether SceneKit applies High Dynamic Range (HDR) postprocessing effects to a scene.


A logarithmic bias that adjusts the results of SceneKit’s tone mapping operation, brightening or darkening the visible scene.


The luminance level to use as the midpoint of a tone mapping curve.


The luminance level to use as the upper end of a tone mapping curve.


The minimum exposure value to use in tone mapping.