Different appearance between material preview, viewport shading, and rendered image

Question

For some reason, when switching between different viewing modes, as well as rendering through a camera, my image texture is appearing differently for each mode. I have it set up to assign one of two materials (red or blue) based on this image:

In , it works great and does exactly what I want it to do, snapping each color to one chair. However, when I switch to or try and render it, the texture gets all weird and appears to somehow assign two materials to one seat.

Wondering if there is a way to fix this so that each seat has one color and that the colors between viewing modes match

Answer 1

The blue chairs are everywhere, and the red chairs are only there where they form the text. This means in parts where a red chair is you also have a blue chair at the same time. When you try to render it, Blender cannot precisely decide which face to show, either the red or the blue one. This is called Z-fighting.

Since the selection of the red chairs seems to be correct, you don't need blue chairs where the red ones are. So instead of creating some kind of selection for the blue chairs and plug it into the Instance on Points node, you can simply invert the red chair selection by using a Boolean node set to Not and take that for instancing the blue chairs.