Flashing objects

Please see the attached file. Why are the wheels flashing? I’ve not seen this before on a project. Thanks in advance!
Train Section.lbrn (2.1 MB)

What’s happening is that you have the same marching ants effect that you get whenever you select an object.

However, what’s different about the shimmering objects is that they’re actually made up of a whole lot of tiny lines that are disjointed. This plus the marching ants is giving it that flashing appearance.

Hi and thank you for the response. Can you tell me what you mean by disjointed? I don’t see disjointed lines when I blow up the image. Thanks!

The lines are aligned in such a way that their ends are perfectly butted up against each other. However they are not actually joined in a way where the nodes are stuck together.

Note how these lines appear identical:
image

However, upon closer inspection you can see that the top “line” is in fact 2 separate lines that just happened to be aligned. The bottom line is a single line made up of 2 line segments joined together at a node.
image

Thank you so much for the explanation!