UMG Retainer Box issue with Opacity

Development Programming & Scripting UI
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1

Hello there,

I get an issue with the Retainer Box where it’s Opacity behaves strange (4.19 - 4.25.3). I found a question on the Answerhub which is a bit similar but not the same issue like mine.

This screen shows the issue (2 borders, both with the same color/opacity, right one rendered with RB, the left one not). As you can see, the border rendered with the retainer box has another opacity.

309320-rb2.png
309320-rb2.png2560×1440 26 KB

This screen shows the setup in UMG:

309322-rb-withmat.png
309322-rb-withmat.png2560×1402 275 KB

This screen shows the RB Blend Material, I am pretty sure that it has something to do with the material output, but I can not figure out what I’m doing wrong:

309323-rb-mat.png
309323-rb-mat.png2560×1398 366 KB

This is the blend without Material:

309324-rb-nomat.png
309324-rb-nomat.png2560×1405 270 KB

309325-rb-nomat-result.png
309325-rb-nomat-result.png2560×1440 25.5 KB

Does anyone have an idea? Thanks in advance!

2

Did you read the tooltip for Effect Material? Maybe that’s what you’re doing wrong?

2 Likes
4

RetainerBox Effect Material Tooltip text as of Unreal 5.5:

The effect to optionally apply to the render target. We will set the texture sampler based on the name set in the @TextureParameter property.

If you want to adjust transparency of the final image, make sure you set Blend Mode to AlphaComposite (Pre-Multiplied Alpha) and make sure to multiply the alpha you’re apply across the surface to the color and the alpha of the render target, otherwise you won’t see the expected color.