Why am I seeing this light banding?

Development Rendering
1

In the screenshot below, you’ll see the light has dark lines through it as it falls off, almost pixelated looking around the corners of the light.

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138265-screenshot.png659×502 245 KB

I’ve read that this could be caused by shadow bias, but changing the values seems to have no effect on it all. It’s a static light though and I didnt do a light rebuild (but it didnt tell me one was needed). It was last rebuilt on production quality as well.

all the advaced light settings are default, all I’ve adjusted is:
source length, intensity, and attenuation radius.

my objects around it (in this case the ceiling) have very good light map density, about greenish-yellow.

If anybody could give me some suggestions it would be really appreciated, as this is one of many lights in my level doing this.

2

I somewhat recreated your scenario, try setting ‘Shadow Bias’ and ‘Shadow Filter Sharpen’ both to 1. This seems to get rid of any artifacts/pixellation for me at least. I don’t know what performance impact either of these settings will have, so do your own research if they work for you.

3

Did you do a light rebuild afterwards? and to quote the UE4 docs directly about the shadow filter sharpen “This final example shows the Shadow Filter Sharpen property, which is used to boost sharpness at the edges of shadows. It is only useful on Movable or Stationary lights, and only works with shadows from dynamic objects.” and my light is static so that has no effect on my light.