Render Target 2d Export PNG Appeared Darker

When I use CaptureScene2D to capture scene using “Final Color (LDR) in RGB”, and store it in a RenderTarget2D with a RGBA8 format, the captured image is much darker than in viewport, And after I export it to a PNG file,it appears even darker,and with unwanted alpha channel.


What it should look like:

Captured to aRenderTarget2d:

Export to PNG,and import to UE to see how it look like:

BTW I use TAA for the capture and captured multiple times to get better TAA result. TAA works fine,but only darker. I simply want to capture the image which is exactly look like which is in viewport, What did I miss?

Have you solved this problem?

Yes…well kinda…
To get the same brightness in capture, I tweeked the postprocess\Tonemapper\Slope=1,Toe=0,and it gives me a relatively accaptable result.
And to get the right PNG output,I set the render target gamma to 1.001. NOT 1, 1 will not work…,
These settings solved my problem, but the result is still a little pale than the original image…
I can’t help myself to say this: Why O why is it so hard to get a simple render output ???

Hey I just found the solution!
I found out that viewports are using gamma correction(=2.2) but the scene captures are not,so first set the gamma in render target to 2.2,then is the post proccess material, add a power node to the final result,(exp=2.2),then export to png,you will finally get the exact result like it’s in the viewport.

1 Like

Thank you so much

You are a life saver.

UE4.26.0 Same problem when using the Composition Framework for Virtual Production. Exported RenderTargets are to dark. Changing the Gamma value in the RenderTarget did not change anything for us. The material trick worked, though we used exp=1/2.25 to brighten the image (values < 1 result in even smaller numbers when multiplied (exponent) with themselfs).

But when importing a texture into the editor, it looks the same. Thus the image is gamma corrected when imported?