Error in the refraction and reflection of glass

[martindrake81]

We are rendering a long flythrough camera (about 2000 frames) Settings are IR map for first bounced - multiframe incremental, light cache on flythrough for the secondary, glossies are calculated in the LC.
Other unusual stuff is that the exposure on the camera is animated as the path travels through exterior and interior areas.

We are getting an error where surfaces facing upwards and through glass are rendering a bright light blue colour. The error also appears in the reflections of the glass as well as the refraction.

Help please! Thank you

[Neilg]

Looks like reflection depth - check the floor material and make sure max depth is off in the main render settings.

[martindrake81]

Thanks Cubicle gangster.

We actually fixed it in the end by changing the 'sample look' to 'Density based (best)' from 'Overlapping' in the irradiance map.