Precision loss in vertex shader

There is a bug (feature?) in UE5 that reduces the precision of object transforms (rotation, scale) for about an order of magnitude. I have been complaining about this since 5.0 first came out and reported it several times. Since Epic for some reason doesn’t want to list the bug I am posting here about it so that at least other people can be aware of it not waste time trying to figure out what is going on (like me).

I’m mostly posting because I finally found a workaround.

This image shows the test setup zoomed out.

this is UE5(.0,.1,.2) default behavior. The shape is rendered in wireframe and you can see the corner is not where it is supposed to be (where the sphere is)

This is the same thing but with the workaround applied and the corner is now following the sphere correctly.

This is what you have to do, to regain the lost precision.

Hopefully this can one day be fixed. Until then if you have meshes big enough to show this problem, you can at least get around it.

Over and out :).