Here is a shorter forum-ready version:
I’m using a Line2D mask that is written into a Render Target (RT), and then the RT is used inside a UMG material.
Pipeline:
Line2D → multiplied with color → Render Target → UMG material
The issue is:
If the Line2D result is multiplied with blue (or strong blue tones), the final result becomes invisible in the UI material. Other colors (red/yellow/etc.) work fine and remain visible.
Even if I apply the blue color again in the final UMG material, the result is still not visible.
The Line2D mask itself is confirmed to be clean (0–1), and the RT sampling looks correct in other cases.
It seems like blue/green channels are being lost or heavily attenuated during the UI rendering pipeline when combined with the Line2D mask.
When I use the same node and simply replace the output color with red, the UMG material correctly displays the Render Target result!？？？？？？？
