Gee thanks::Blushes:: Hi Maga, First of all,are you also selecting "Infinite Light from the light editor? also check you Falloff( Linear,squared ,ranged, also...is your sky an infinite skyplane? ,if so , try selecting "Disable cast shadows" if it's not an infinite skyplane, try turning off cloud shadows from the sky lab under the sun/moon tab. also ( I know I say that allot) do you have anti aliasing turned on or off? as far as the reflective ground,is there something driving the bump channel that could be reflecting the lines? one more thing (I Promise) sometimes If you render in an orthogonal non perspective mode(from right,from front,etc.)it's gives weird lines, just an afterthought. these are the things I'd try first, but if it doesn't help, try posting a sample for us to see exactly what this artifact looks like. hope this helps though. Hawkfyr

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