P3D HDR Brightness tweak

[Chris Bell 144]

I have found a way to increase the brightness with HDR enabled.

In the shadersHLSL/PostProcess folder is a file named ' HDR.hlsl '

Make a backup of this file elsewhere, then load it into notepad or similar editor.

At line 166 you will find ' //avgLuminance *= 0.85f; ' which is commented out by the two slashes.

remove the two slashes ie: ' avgLuminance *= 0.85f; ' and save.

If you want to experiment with this value, increasing it makes the image darker, decreasing makes it lighter.

I haven't determined whether it messes with the overall HDR experience, but the programmer put this line in and it seems to work.

Note: In my case, just saving and running P3D worked the first time, but later runs of P3D resulted in a black (blank) screen.

The solution was to ensure that the associated compiled shaders in the ' C:\Users\Yourname\AppData\Local\Lockheed Martin\Prepar3D v2\Shaders ' were deleted.

As I understand it, the HDR code looks at the average brightness of the display and boosts it adding bloom to simulate the effects of light and dark.

The stock code seems optimised for a standard display.

Those of us with triple screens have much larger display area that often includes parts of the side window views. This extra brightness has the HDR overcompensating and resulting in a darker than desired screen. Changing the code at line 166 seems to tell the code that the average brightness is less, therefore add more brightness.

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Another option which leaves the rest of the code alone, is to increase the return value of the ' Composite ' function.

Insert ' final *= 1.2f; ' just before the last line of code

eg:

bloom = bloom * BloomMagnitude;

// Add in the bloom

float3 final = color + bloom + brighten + dither;

final *= 1.2f;

return float4( final, 1.0f );

}

So far I prefer the above option. Note: setting a value too high causes bright parts to clip.

source

http://forum.avsim.net/topic/451123-brighter-hdr-tweak/