I’ve figured out that if I turn off “adjust reference” I can get the effect that I want, but then I can’t centre the GUI nodes as before. How do I centre a GUI node when adjust reference is disabled so that it’s in the centre of the screen?
To be specific: the box in the image rotoatea around the Y axis. when the rotation was at 90° (i.e. should be invisible to the player), some strange blurred lines, the same colour as the sprites, would appear above and below the sprites.
I don’t know what material I am using, sorry. The problem is solved now anyway (and I, luckily, have not yet had to spend too much time looking at materials, etc.)
Those are just colored box nodes with no texture? The edges will always be sharp, since it’s the edge of the mesh. You can try using a flat square texture with a 1px border around it, so the edges will be anti-aliased.