Consistently sized rivets among UV shells?

[phaedarus]

Hello everyone,

I'm working on a vehicle model with the aim of creating rivets and panel lines via normal mapping.

It's a struggle for me as I attempt to make the most of my UV space but this inevitably results in abnormally sized rivets between different UV shells.

I could size the UV shells so that they are roughly the same size with a checkerboard pattern as reference. However, the UV layout tools tend to make them less efficient use of UV space this way and I don't have the option of scaling down UV areas that seldom seen by the player in order to give the more important UV shells more resolution.

Is there a trick or method for maintaining consistency for small details that follow a pattern between UVs?

Thanks.

[Benjammin]

Well, you should actually try to keep your UV shells at a consistent scale across a model to maintain a uniform texel density. Its not such a big deal with higher end systems, but generally speaking, non-uniform texel density makes a system work harder to draw a mesh and may introduce artifacts. See this article for more detail: Beautiful, Yet Friendly Part 2: Maximizing Efficiency (Its a bit old but the principles are still valid)

But, to answer your question - if you use Zbrush or a 3d painting package to draw directly onto your model you'd be able to maintain consistency.

[mmcleo11]

The UVs should all be scaled roughly to the same scale e.g. typically 3rd person AAA titles adhere to 4:1 pixel ratio.

This way after a few baking test you will be able to know the scale of the details like rivets/scews that you can get away with in game before they turn into pixel noise.

[phaedarus]

Thanks for the responses.

What exactly is the 4:1 ratio?

One of my main motivations for enlarging the UV shells for certain parts of the vehicle was to accommodate text labeling as they tend to be blurry more often than naught. Looks like I may have to resort to decaling - seems like wasted texture memory though.

[Piflik]

1 pixel in screen space is 4 pixels in the texture, so if an object has 256px side-length on the screen, the texture should be 512px square.