New Bevel shader darkens transparent materials
Closed, ResolvedPublic

Description

System Information
Win10 x64, nVidia GTX 1080Ti

Blender Version
Broken: Current builds (since the addition of Brecht's new bevel shader)
Worked: none so far

Short description of error
Adding Brecht's awesome new Bevel shader to transparent materials makes them render a lot darker.
The darkening becomes more prominent the more samples you use in the Bevel shader.

Exact steps for others to reproduce the error

  • Open this blend file:

It's just a simple cylinder with a thin wall and a Principled shader with transparency and a constant white environment.

  • Render
  • This is the result:

  • Go to the cylinders material and plug in the Bevel shader. Render again.
  • Now you get this result:

  • If you set the samples in the Bevel shader to something like 16 the cylinder becomes completely opaque.