Firstborn/Library/PackageCache/com.unity.postprocessing@3.2.2/Documentation~/Auto-Exposure.md

Auto Exposure

The Auto Exposure effect simulates how the human eye adjusts to changes in brightness in real-time. To do this, it dynamically adjusts the exposure of an image to match its mid-tone.

In Unity, this effect generates a histogram on every frame and filters it to find the average luminance value. This histogram and the Auto Exposure effect requires Compute shader support.

Properties

Exposure settings:

Property	Function
Filtering	Set the lower and upper percentages of the histogram that find a stable average luminance. Values outside of this range will be discarded and won't contribute to the average luminance.
Minimum	Set the minimum average luminance to consider for auto exposure in EV.
Maximum	Set the maximum average luminance to consider for auto exposure in EV.
Exposure Compensation	Set the middle-grey value to compensate the global exposure of the scene.

Adaptation settings:

Property	Function
Type	Select the Adaptation type. Progressive animates the Auto Exposure. Fixed does not animate the Auto Exposure.
Speed Up	Set the Adaptation speed from a dark to a light environment.
Speed Down	Set the Adaptation speed from a light to a dark environment.

Details

Use the Filtering range to exclude the darkest and brightest part of the image so that very dark and very bright pixels do not contribute to the average luminance. Values are in percent.

Minimum/Maximum values clamp the computed average luminance into a given range.

You can set the Type to Fixed and it will behave like an auto-exposure setting.

You can debug the exposure in your scene with the Post-process Debug component. To do this, add the Post-process Debug component to your Camera and enable the Light Meter monitor.

The Light Meter monitor creates a logarithmic histogram that appears in the Game window. This displays information about the exposure in your scene in real time. For more information, see Debugging.


The Light Meter monitor.

Requirements

• Compute shader
• Shader model 5