Hello, I add a point light with hard shadow and i get black stripes on walls when it’s on in low resolution shadow, so i search how remove them or reduce. Thanks.
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Try tweaking the shadow bias value in your light.
I get the same problem when there is a very small angle between the plane and the light.
The only solution that I found was to turn off shadow casting for the object.
It’s a bit sad that no one from unity has answered this question in over a year.
Do they not care about their paying customers?
Thanks a bunch Louis.
It so happens that I’m lighting the large rounded corner of a building with directional sunlight that needs to be on one side and not the other for narrative reasons…
But I guess I’ll have to think of a different architecture or something 
If anyone stumbles across this in 2018+ , in your directional light under “shadows” try increasing the resolution. It will get rid of banding on steep angles.