High-dynamic-range rendering

Video games and computer-generated movies and special effects benefit from this as it creates more realistic scenes than with more simplistic lighting models.

HDRI languished for more than a decade, held back by limited computing power, storage, and capture methods.

[4] In 1995, Greg Spencer presented Physically-based glare effects for digital images at SIGGRAPH, providing a quantitative model for flare and blooming in the human eye.

In gaming applications, Riven: The Sequel to Myst in 1997 used an HDRI postprocessing shader directly based on Spencer's paper.

[8] After E3 2003, Valve released a demo movie of their Source engine rendering a cityscape in a high dynamic range.

With higher contrast ratios, it is possible for HDRR to reduce or eliminate tone mapping, resulting in an even more realistic image.

HDR rendering also affects how light is preserved in optical phenomena such as reflections and refractions, as well as transparent materials such as glass.

Adaptation is achieved in part through adjustments of the iris and slow chemical changes, which take some time (e.g. the delay in being able to see when switching from bright lighting to pitch darkness).

[citation needed] The simultaneous contrast of real content under normal viewing conditions is significantly lower.

Some increase in dynamic range in LCD monitors can be achieved by automatically reducing the backlight for dark scenes.

Since the 2010s, OLED and other HDR display technologies have reduced or eliminated the need for tone mapping HDRR to standard dynamic range.

This tone mapping is done relative to what the virtual scene camera sees, combined with several full screen effects, e.g. to simulate dust in the air which is lit by direct sunlight in a dark cavern, or the scattering in the eye.

Various tone mapping operators exist, ranging from simple real-time methods used in computer games to more sophisticated techniques that attempt to imitate the perceptual response of the human visual system.

HDR displays with higher dynamic range capabilities can reduce or eliminate the tone mapping required after HDRR, resulting in an even more realistic image.

DirectX 9.0 introduced Shader Model 2.0, which offered one of the necessary components to enable rendering of high-dynamic-range images: lighting precision was not limited to just 8-bits.

One of the first graphics cards to support DirectX 9.0 natively was ATI's Radeon 9700, though the effect wasn't programmed into games for years afterwards.

At first, HDRR was only possible on video cards capable of Shader-Model-3.0 effects, but software developers soon added compatibility for Shader Model 2.0.