I create camera "FILM offset" but I find some question about screen color

hi, I rebuild unreal engine for camera “FILM offset” , I modify perspective matrix in PerspectiveMatrix.h.
the following is the code I change:

FORCEINLINE FReversedZPerspectiveMatrix::FReversedZPerspectiveMatrix(float HalfFOV, float Width, float Height, float MinZ, FVector2D shift)
	: FMatrix(
		FPlane(1.0f / FMath::Tan(HalfFOV), 0.0f, 0.0f, 0.0f),
		FPlane(0.0f, Width / FMath::Tan(HalfFOV) / Height, 0.0f, 0.0f),
		FPlane(shift.X, shift.Y, 0.0f, 1.0f),
		FPlane(0.0f, 0.0f, MinZ, 0.0f)
		)
{}

the “FPlane(shift.X, shift.Y, 0.0f, 1.0f),” is my modified part.

but when I try to stitch two screen(same camera but diffent shift.X), why the screen color is difference so great?

You need to turn off Eye adaptation in the post process effect settings. Eye adaptation will automaticly change the exposure based on the focus point.

Here is more info on the topic:

thanks, I stitch look like OK after set Max brightness and Min brightness to 1.0

I’ve been trying to find a way to achieve this camera offset for a game I’m working on. Could you share details of how you achieved this?

Hi! Would you mind to explain me, how you rebuild UE4 with this code in your topic? I need it for my student project with projection mapping

would be grateful to understand how you achieved this as well!