Is there any UV-SOP to edit an existing UV (sew, cut, ... like UV-Flatten)?

[Masoud]

Hi;

I want to sew, cut, and all editing things which I can do in the UV-Flatten SOP, on an existing UV.

The reason I don't use the UV-Flatten is I don't want to start defining UV seams and islands from scratch.

Is there any UV_SOP for it?

 

Thanks for helping.

 

[anim]

create seams group using Group From Attribute Boundary, use that group in Seams parameter of UV Flatten and then you can use viewport state to cut and sew them further, it will redo your layout however

Edited May 8, 2020 by anim

[davpe]

hi, there is a Fuse UV SOP that you can use to sew pre-existing seams, but it doesn't work as conveniently as you wish for - it works basically as a normal Fuse SOP and fuses any points that are in proximity radius. So you have to manually align uv islands first (and maybe group them) and then fuse them. Kind of sucks, but will do the job if it's not a heap of seams you need to sew.

For other kinds of edits, you can use UV Flatten SOP, and say "Preserve seams" and "Preserve layout" - that should keep the original uvs intact, and you will be able to do edits on top of it (with exception of fusing pre-existing seams which is a shame). But to be honest I found the "preserve features" in this node not to be working great every time (it always tries to remove uv distortions so if the original uvs were distorted it will still relax them a little). Most of the time what I do in such cases, is to split the geo and work only on pieces I need and then merge them back together. I agree UV Flatten SOP could use some more polish. Maybe a RFE?

[Aizatulin]

Hi,

not sure if this can help you, but have you tried to convert your uvs to point positions ? Perform your operation for points (which represents uvs) and convert them back to their former positions. While your uvs are in the point space, you can apply usual point operators

on it. It works a bit different, for example for fuse you should turn off "fuse snapped points", because you want to keep all points existing points. Haven't done alot with this, but here is an example file if interested. 

uv_to_pt_example.hipnc

[Masoud]

3 hours ago, anim said:

create seams group using Group From Attribute Boundary, use that group in Seams parameter of UV Flatten and then you can use viewport state to cut and sew them further, it will redo your layout however

It changes my layout

[Masoud]

3 hours ago, Aizatulin said:

Hi,

not sure if this can help you, but have you tried to convert your uvs to point positions ? Perform your operation for points (which represents uvs) and convert them back to their former positions. While your uvs are in the point space, you can apply usual point operators

on it. It works a bit different, for example for fuse you should turn off "fuse snapped points", because you want to keep all points existing points. Haven't done alot with this, but here is an example file if interested. 

uv_to_pt_example.hipnc

Sorry, but I think it's not a very practical workflow...

[anim]

5 hours ago, Masoud said:

It changes my layout

maybe pin it before starting sewing, then unpin parts you want to move and join others, not sure if you can unpin in viewport though