After you download and extract the Area Light Map texture, start Maya and drag the ".exr" file to the Hypershade Editor.
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On the Arnold shelf tab select create Area Light.
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Select the Arnold Light object, open Hypershade Editor and then drag the texture node by clicking and holding middle mouse button to the color texture.
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After you assign the texture your Area Light reflection will be updated.
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Go to Arnold shelf tab and select Arnold RenderView and render your scene.
