3DSmax - UVtools - Straighten selection messes with spacing?

capone

Here I have peeled a UV island. Relaxed it and the space between the vertical lines are correct.




but if I use the straighten tool it sort of ignores/automates the distancing between each segment. In Modo it seems to do a better job of calculating this when straightening. Is there anything I can do with Max's unwrap tools to ensure it keeps more faithful to the original spacing?

poopipe

I tend to do it one loop at a time. I've got some scripted buttons that work like maya's align uv tools so I can align to top/bottom etc. Extents

If it's on a cylinder I just use a cylindrical unwrap with normalisation turned off instead of fannying about 

musashidan

As well as the 2 methods mentioned, there is also unfold strip from loop. And sometimes I'll just flatten mapping and use my stitch hotkey to piece it together quickly.

Straighten sometimes f##ks up and you just have to fix it yourself. Like @poopipe I have align vertical/horizontal on hotkeys. If you use the peel mode(for non-perfectly cylindrical islands) then don't relax the island straight after, use the pins to pull it straight and then manually align the borders. Very fast with hotkeys.

And also, another method is to straighten the island borders and relax it with boundary points fixed. This works exactly like HeadusUV rectangle tool.

There is always going to be some trade-off between distortion and straightened islands. Personally I don't mind a little distortion if it means I have nice straight border edges for baking.

Altea

I had a few times that issue and I had the impression it was a bug. I solved it selecting the full object and applying a "quick planar map". Nothing else seem to work. 

Then doing exactly the same seams and UV steps the straighten tool works perfectly.

Problem:

Solution (or at least works for me) quick planar of the full object and redo the UVs. Perhaps there are other workarounds for this bug. 

capone

Lots of interesting ideas here. I was also messing around with UV's from spline method but it always results in the same problem. Plus it takes extra steps to get there. It's a weird one, Maya/Modo seem to just magically predict what you want and keep the spacing pretty much spot on. It's an issue I remember bringing up 5 years ago but there was no solution so I just thought it was never going to happen. Since then however I've been spoiled by Modo, unfortunately I need to use max for my current project.

Altea

The system I suggested is the only that allows you to keep using the straighten tool. I wonder if there is a way to do it quicker without being forced to use a completely different tool.

poopipe

There is sometimes an issue with peeling/pelting etc. where the uvs get large offsets in the W channel - that can mess with any functions that take uv face area as a parameter.   If you're getting weird behaviour, switch to uw (not a typo) view and make sure everything is zeroed in w before panicking 

Altea

How can I zero it when in UW?
That solves the problem, but the only way to move the verts to 0 that I can see is to select them and move them manually, that seems cumbersome and imprecise. I suppose there is a better way to do it.

Eric Chadwick

Select all the UVs and set W to zero.

Altea

When I select all faces or edges or verts I get the U and V that I could type, but W is empty and not accessible

Eric Chadwick

Change to UW first.

Altea

That is already the UW view, that is the reason why it shows the elongated UVs that highlight the problem. The problematic verts are pins created by the quick peel.

This how looks in UV view

Altea

It is possible to use vertical scale, as long you place the pointer just in top of the elongated faces. It yet feels cumbersome but it works. 
It would be handy if anybody suggest how to move them to 0 in a easier way but in any case a big thanks to Poopipe. I had this problem lots of times and I had no idea how to solve it until now.


By the way this is evidently a nasty bug. Tested with Max Unwarp pro plugin from Silagui and it has not this problem.

monster

Swordslayer

@monster wouldn't that mean you'd have to select the offending verts one by one to flatten them that way? Or are you aware of a way to change it from moving center of the selection only to individual verts in unwrap?

Altea

Thanks, that works. Also instead select all verts I need to select the ones that share the same distance to 0, otherwise it simply shift all selected keeping proportional distances.

Scaling all verts with only scale vertical also works fine.

monster

I see, I was just explaining how to enable the W box.

But setting W to 0 is one line of script.

selection[1].unwrap_uvw.movez 0.0

Altea

Thanks, the script works. In fact you don't need to go to UW mode. As soon you select all verts in UV mode and run this script the problem is solved.