Shadow shows opposite color in rendering

[Anonymous]

The two materials are glass and show up opposite in sunlight vs shadow..
Any ideas?

[Steve Jepson]

If they were mirrored from the corner, perhaps some of the glass is inside out?
What happens to them if you trade places without changing which side is out?

[Erwin Edel]

Think this is 'just' refraction doing its thing, but you could also check how many layers of transparancy are being rendered.

Go in to Detailed Settings, all the way at the bottom there is Options > General Options.

Look for Ray Treshold, Ray Depth and Reflection Depth.

Try setting the Treshold to 0, this will reflect everything in your scene, sometimes the cut off percentage gives weird results. Render times will increase a bit.

Ray Depth and Reflection Depth are how many layers of transparancy will be passed. I ussually have these around 12 both to allow enough windows to be shown. This will also increase render times a bit.