Bug report - Rendering - Opaque layer shows random blocks of see through

[stianstrips]

I am in the process of creating a model of my Oneplus phone and wanted to create a realistic looking display.

I'm unable to create a completely opaque layer between the glass and phone body. This is of no big consequences for me as it's just hobby but this looks very much like a bug to me. So this is not a post where I'm looking for a workaround. This is solely for reporting purposes.

The blue artefacts should not be there on the render.

Model layering:

1. Clear glass (ca. 0.5mm thick) (turquoise)
2. Emitting (LED) letters embedded in the opaque layer (0.005mm thick) (pink / peach colour)
3. Black opaque layer, tried black opaque plastic and steel materials (ca 0.01mm thick) (yellow)
4. Blue anodised aluminium body (green)

 

The reasons the opaque layer got so thin is because I didn't have it at first and trying to just change the faces on top of the body was tiresome. So I shaved off a thin layer of the original display glass to use as a "blackout" layer.

 

Renders show larger blocks of blue shining through but they change whenever I modify materials / appearance. Preview rendering shows moire like patterns shifting when changing angles on object.

I have attached the model and diagnostic logs.

Regards

Stian

[stianstrips]

I saw a similar issue reported here I'm not able to find again. The workaround there was to add a bit of space between the layers.

So I tried this and added 0,01mm space between the blue body and the blackout layer and it worked perfectly.

This kind of confirms the issue to be a bug in my book. A layer of material should not become randomly transparent when another layer touches it.