roeland wrote:Is this problem still present in version 4.02? I can't see any difference in behaviour with 3.07 and 3.08.
What you see in that cube is total internal reflection. Areas where light is reflected are always rendered as opaque even with “affect alpha” switched on.
Please check the latest scene i posted for better understanding (room interior). That's easiest to explain the problem.
Works in 3.06 and 3.085, broken in 4.0.1 and 2018.1.0.3 (i've not tried in 4.02 since it ha some other bugs people reported) and 2018.1.0.3 is probably inherited same from 4.x so since problem is still there.