Operating system: Darwin-15.6.0-x86_64-i386-64bit 64 Bits
Graphics card: Intel Iris Pro OpenGL Engine Intel Inc. 4.1 INTEL-10.14.74
Broken: version: 2.81 (sub 9), branch: master, commit date: 2019-09-09 17:22, hash: rB6be3348505ce
Short description of error
When using Scattering Radius, we can adjust the scattering effect per RGB channel. The problem is when one of these values is very low, near to zero. We see a reflection on the surface of that channel.
Exact steps for others to reproduce the error
01 object with principle shader and set Scatter Radius to R=.6, G=.35, B=0, basic gray color diffuse, soft roughness
02 Add HDR with strong lighting from 1 side and add perhaps sunlight (power 1, angle 5deg)
03 You see a blueish highlight apear on this material
See attached scene and example shots
left bl 2.79 - right bl2.81 > alterered material darker for better highlight
left bl 2.81 - right bl2.79
left bl 2.81 with Scatter Radius Blue 0.02 - right bl2.80 with Scatter Radius Blue 0.00
Here's another example, simplified material to show the scatter effect. Left is bl280 right is bl279
Is it perhaps due to the number 0 that blue light shows at the surface of a model? This cause weird reflections. I bumped into this from a scene from Rico Cilliers. I believe it was made in an Beta bl 2.80 in december 2018
After some talk with him, he noted that there an issue with Scatter Radius in the beginning. Number of zero or near zero would cause this weird haze/reflection.