I've been having a problem with a weird shadowing effect on the edges of some of my curved square cylinders. I'm not sure how to get rid of them because they show up in every type of compile that I do. I usually just try to use darker textures to keep the shadows less distracting but sometimes that's unavoidable.
Here is a screen with a very pronounced version of the shadow.
It's on the arch in the middle of the screen where the bricks line the edge of the curve.
Hmm, if it's one square cylinder, maybe break it up and use two.
But better yet, use two 5x3 simple patch meshes, because 50% of that square cylinder isn't visible anyway, as far as I can tell from the pic.
Have to get it right, to avoid LOD tears, though.