HDR Bloom Tonemap

The HDR bloom tonemap effect provides two features:

  • Adjust the gamma and exposure of the high-dynamic range rendered content to achieve the image quality you want.
  • Apply an adjustable bloom effect to very bright areas (like the sun glinting off a car).

In the image below, the effect is applied in the right picture.


GammaAffects the non-linear curve of the lighting. Higher values increase the exposure of mid tones, lightening the image (and decreasing the contrast). A value of 1.0 causes no adjustment to the image.
ExposureA linear multiplier on the lighting, brightening, or darkening the image overall. A value of 0.0 causes no adjustment to the image.
Bloom thresholdLighting greater than this value blooms. A value of 1.0 corresponds to white in the original render result. Lowering this value causes more areas of the rendered scene to bloom; at a value of 0.0 everything in the scene blooms.
Bloom falloffAdjusts the amount of bloom. Lower values result in stronger bloom effect; higher values make the effect more subtle.


To disable bloom and use only the tone mapping, set Bloom falloff to a sufficiently high value, like 999.

Available under certain Qt licenses.
Find out more.