Blender 2,91 error / bug?

I jusut stumbled upon this wierd issue where some faces on mesh are black and when I move the mesh it seems the area where the faces are black is like in area that blakens everything that passes that area. Also when I change emission from my shader it seems that the color is linked to that though it should not be since I use only basic prinsible shading only change is the color white nothing else. I tested to remove all from the scene, but that doesn’t help. also when I take render of the area it doesn’t come into the render it is only visible in other modes, but can’t be rendered out ???

Also as you see normals are facing right way, but even when I change normals to inside it doesn’t change anyhting. It seems like there is some invisible hovering mesh that keeps interfere with the mesh, but it can’t be seen or deleted or anything ??? Without answers to this problem to me it seems this is a bug of the latest release 2,91 which I downloaded 2 days ago.

I have noted the same strange problem with the principled BSDF (what you’re using) being automatically set to an emission strength of 1. I’ve also had weird problems in the render preview, and with renders coming out like crap even with denoising turned on. Are you having any problems with lighting in interior renders?

I’m beginning to think the devs changed something fundamental with this version, of the installer for 2.91.

I haven’t noticed anything else. I’m pretty noob with blender so I haven’t done anything complex, but I know that this shouldn’t happen and the principle is basic I haven’t touched anyhting and also forgot to mention that I tested to make new priciples bsdf and still it gave same results. This happens in cycles only btw in eevee it looks white like it should be

Problem solved!!!

It seems that blender created some sort of link with faces on outside the A letter and few other letters and faces that were inside on these letters facing some random direction. I went through all of the mesh and removed all faces that were inside different part of different letters and dark faces are now gone :slight_smile:

I think the link is that this is one mesh from which I have done al lthe letters.