[atoav]

I am foemer VFX freelancer who worked for cinema production and was specialized on "invisible" VFX.

Making things non-uncanny is usually about two things:

1. The amount of work/time you can put into a single thing

2. Your ability to see

The latter is basically the same reason why people are unable to draw things realistically, that they see on a daily basis. Your brain is very good at giving tou just a conceptual picture of a much more complex reality. Artists for whom realism is important have to have the ability to look at things as they hit the retina and not get blinded by that abstraction in the head.

This is the foundation of achieving any kind of realism (and there is more than one realism, you can also take photographs that look uncanny).

In this case I think it is about materiality. This is typically about a lack of imperfections or a lack of taking the way things are manufactured in the physical world into account: The motar in a brick wall isn't made up of perfect uniform lines, concrete is casted, walls painted in certain ways, outside objects are exposed to the weather, but not uniformally so, etc. This is very often about very small things like subtle variation in the albedo/roughness etc.