Principled BSDF - Roughness = 0 - BAD!

2.93.2 - Eevee.

Make a cube.
Make a Principled BSDF for the cube.(Mine is green)
(The default Roughness will be 0.5)

Set Roughness to 0.000. The cube is now black.
.
.
ruf0

.
.

Set Roughness to 0.001. The cube is still black.
.
.
ruf001

.
.

Set Roughness to 0.010. And BOOM ! The color shows up.
Why is that?
.
.
rof01

I’m unable to recreate this in either 2.93.5 or 3.0,
It’s either a bug or a driver issue. My guess would be driver issue given how ubiquitous it would be as a bug.

Not sure if it is a bug or a driver issue, are you using an integrated graphic card?
This reminds me of this bug/issue and this thread:

https://developer.blender.org/T88754

(I have no idea why the thread has a no entry sign) but I can still read it. :thinking:

No.

I am CPU only - Intel(R) HD Graphics 4600. Windows 10. I am but a simple hobbyist.

Now that I know how to fix it, it’s no big deal. Just curious if others have this issue.

Happy Blending !

Was a bug now solved https://developer.blender.org/T88754

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Ok.
calpgrmr’s problem reminded me of it.

WOW!

Thanks so much. Was avoiding new versions of Blender, but may give it a try!

They just dropped 2.93.6, hopefully the fix is included.

Again Thanks!

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For future reference, yes you are. ‘Integrated graphic card’ means you don’t have a separate physical graphics card but instead it’s integrated with the CPU.

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Oops. Guess I had that backwards in my head. Thanks. (duh) :pensive: