Rendering Glass (layers) resulting in strange dark patches (in Final but not Preview) I am working on a school research project and hence I cannot share the blender file (confidentiality BS). I am getting strange lines in the render where there are stacked "glass" tiles. This occurs only in the final render and not in the preview render. I have tried the following but to no avail:


Increasing spacing in between (the tiles are not touching each other)
Increase light rays
Smooth Shade Toggle and Edge Split Toggle
Toggling Caustics
Changed Material from Glass to Principled shader


Blender File: https://drive.google.com/open?id=1OERauRJs8S7BAYAZq7S64UlmmxdvrcSL



Final Render (500 samples)



Preview Render (32 samples)



Final Render (1000 Samples)



Preview Render (1000 samples)
It looks like you have an object hidden in the viewport that is showing up in the render. 

Look for a setting in the outliner similar to this and either hide that object in the render or delete it:



Alternatively, you can press Alt+H, and you should see all hidden objects in the viewport. Then you can select and delete/disable anything you need to.

This script will automatically hide all objects in the render that are hidden in the viewport:

import bpy

for obj in bpy.context.scene.objects:
    if obj.hide and not obj.hide_render:
        obj.hide_render = True




Putting this here for reference...

Why does my object not show up?