headus 3D tools

[Daf57]

Hi,

I hope I can explain this properly. If I unwrap a mesh and get it packed how I want it - I send it back to Max (using a bridge to get back and forth) and then collapse the stack. All is good. I then add some geometry to that mesh. When I choose to edit the uvs all the existing UVs are red - the new geometry is blue. So the problem I'm having is I don't know how to preserve the existing UVs as I had them while adding, and fitting the new ones. SInce they are red at this point I assume I have to re-flatten them (F or Shift-F)? Of course this destroys the packing I did previously as the older UVs change size - sometimes drastically - in relation to the tile. Just wondering if I'm doing all of this incorrectly - must be a way to add the new geometry without completely rescaling? The new geometry is generally small bits - nothing that would really need a complete repack.

Thanks for any suggestions.
Daf

[headus]

So whats happening is that the new geometry you add, which sounds like its just small pieces, is being given relatively large amounts of UV space initially by your modeling software. For example, you add a really small cube, but the modeler will still give that the entire 0 to 1 UV space for its default UVs.

So when you send all that over to UVLayout to edit, its looks at the total surface area of the geometry, and compares that to the total UV area allocated. Adding that small cube only added a fraction to the geometry area, but doubled the UV area. So the original UVs are considered now to be too small, and the new UVs too large, hence the read and blue coloring.

The work-around then is to use the Green Balance button that you'll find at the bottom of the Move/Scale/Rotate tools. Currently its only in the Pro version though, but I'm happy to make that available in the Hobbyist/Student if that's all you've got.

Anyway, with the left mouse button, first select all of the original already packed shells ... the red ones. Click the "Green Balance" button, and they'll be fixed. You should then select just the new UV shells (the blue ones) and click the "&" button on the Rescale row, about half way up that panel of tools. That will shrink those shells down then to match the scale of the original UVs.

Phil

[Daf57]

Oh man! Thank you! That is exactly what I needed! You know I've never noticed the Green Balance button before - but I knew there had to be a way. UV layout is the best!

Thanks again!
Daf

[headus]

I'm glad it worked for you! I always thought myself that the green balance button was a bit obscure and niche usage, but your example shows me how it can be more widely useful, so I need to give it more explanation in the docs.

Phil