UV Workflow & Half automated UV packing

NealAdamLT

Hey Polycounters!

Lately I had to do a lot of UV work and I'm not quite satisfied with my workflow.
Usually I start with making my cuts and sews and then unfolding the model.
If needed, I fix some shells and then let Maya Layout the whole thing. DONE.

But at this point I've ran into 2 problems:

• If I am working with circular objects, the straighten UV tool wont make an UV Straight, but rather make it an edged circle. This results in having to fix the UV Shells by hand, which does the job, but is too time consuming to call it effective. I read, that NSUV (Nightshade UV Editor) has a tool for that, but after trying, I wasn't satisfied either.

• If I want to allign certain UV Shells next to each other, e.g. for weapon camo being in the right place, then I have to place some shells by hand which is totally okay and necessary. But Maya won't allow me to Layout (I am using the "Layout" funktion) the remaining shells around the already placed ones. I can't seem to find an options that enables the Layout function to consider the already placed shells in the UV space.

My question now is: Am I missing something? Or are the problems I have common and there is no fix for them. I totally would consider switching to a dedicated UV Tool like Headus, but would like to stay in Maya to have it all in one programm. Or do I finally have to make the step to 3DS Max? (wich I've wanted to do anyway in the future)

Thanks already for the incoming support ♥

P.S.: If needed, I can visualize my problems

Ghogiel

I'd like to be wrong, but I don't think max will auto pack any better than maya. Both programs could do with some extra functions that I've only seen in 3rd party uv soft.  Like being able to mark some shells or not for rotation in the auto pack and lock or group shells together, so you can do the camo easier in you example or keep material types clumped on the sheet and so on. 

Eric Chadwick

Max allows you to Group UV shells to keep them together during packing. You can turn off Rotation, and re-enable later. It's a bit of a multi step process to do what you're looking for.
http://help.autodesk.com/view/3DSMAX/2019/ENU/?guid=GUID-9E98AEAC-F06F-4FAD-9091-DCD30AC9BB26

NealAdamLT

Ghogiel said:

I'd like to be wrong, but I don't think max will auto pack any better than maya. Both programs could do with some extra functions that I've only seen in 3rd party uv soft.  Like being able to mark some shells or not for rotation in the auto pack and lock or group shells together, so you can do the camo easier in you example or keep material types clumped on the sheet and so on. 

Can you name the one you are using or can you recommend a good one? Just to test things out.

Eric Chadwick said:

Max allows you to Group UV shells to keep them together during packing. You can turn off Rotation, and re-enable later. It's a bit of a multi step process to do what you're looking for.
http://help.autodesk.com/view/3DSMAX/2019/ENU/?guid=GUID-9E98AEAC-F06F-4FAD-9091-DCD30AC9BB26

Seems like one more reason to switch from maya to Max. But the straightening of round UV shells is still as complicated as in Maya, right?

Eric Chadwick

I haven't done it in Maya. In Max if it's a strip made of regular quads, then it's just a 1-click tool. Anything else is about 10 clicks to straighten, + relax.

poopipe

Neither application exposes all the tools available through the UI so it's not always obvious what can be done with button clicks,  a little scripting can go a long way towards making your life better. 

I'm pretty adept with both and honestly for UV work there's not a lot to choose - especially since 2018 came along

I tend to prefer max for splitting my shells initially especially  for unwrapping for anything vaguely complex and prefer to lay out in maya, especially if there are multiple objects to handle. 

I rarely use packing tools unless I'm half arsing something for a prototype but I do use the grouping in max extensively if I'm laying things out with it. 

musashidan

Switching to Max just for unwrapping might be a bit drastic. I'm a Max user and am very happy with the unwrap tools. I used HeadusUVL for years with a bridge script, but now Max has everything I need so I don't have to.

Having said all that I thought Maya received a lot of new UV tools in recent releases?

NealAdamLT

poopipe said:

Neither application exposes all the tools available through the UI so it's not always obvious what can be done with button clicks,  a little scripting can go a long way towards making your life better. 

I'm pretty adept with both and honestly for UV work there's not a lot to choose - especially since 2018 came along

I tend to prefer max for splitting my shells initially especially  for unwrapping for anything vaguely complex and prefer to lay out in maya, especially if there are multiple objects to handle. 

I rarely use packing tools unless I'm half arsing something for a prototype but I do use the grouping in max extensively if I'm laying things out with it. 

So I probably have to get myself into scripting to get things done quicker. If you are not using any packing tools, how do you make sure to use maximum UV space, same texel density and shell padding without spending days for UVing? I'm pretty new, so I may have missed a common workflow while researching.

musashidan said:

Switching to Max just for unwrapping might be a bit drastic. I'm a Max user and am very happy with the unwrap tools. I used HeadusUVL for years with a bridge script, but now Max has everything I need so I don't have to.

Having said all that I thought Maya received a lot of new UV tools in recent releases?

The Max modelling just seems more intuitive sometimes. I did the same before the Maya 2018 release, but now maya provides a bunch of new tools, so in general, a external UV tool shouldn't be needed

poopipe

.. I wrote a tool that sets texel density and I have a load of smaller ones for nudging by pixel distances etc. 
Unwrapping as you go is quite a good idea,  build a part, split the  uvs up,  set texel density and then group them up.  This carries through to instances of course. 

Also in max if you build things in a certain way you often get free or nearly free UVs that would cost you hours  in maya.

The main time-saver is that I've been laying out uvs for 20 years so I've got a bit of a feel for it. 


Spending a decent chunk of time getting a good uv layout isn't a waste,  it's the foundation of all the things that make an asset look good at the end. 

NealAdamLT

poopipe said:

.. I wrote a tool that sets texel density and I have a load of smaller ones for nudging by pixel distances etc. 
Unwrapping as you go is quite a good idea,  build a part, split the  uvs up,  set texel density and then group them up.  This carries through to instances of course. 

Also in max if you build things in a certain way you often get free or nearly free UVs that would cost you hours  in maya.

The main time-saver is that I've been laying out uvs for 20 years so I've got a bit of a feel for it. 


Spending a decent chunk of time getting a good uv layout isn't a waste,  it's the foundation of all the things that make an asset look good at the end. 

Surely it is not a waste, but if I (after cutting sewing, unfolding, orienting and straightening etc.) lay out the UV shells mostly by hand, it would take myself waaaaaaaay longer than running the Maya Layout Tool with a few iterations and then correcting minor things.

For example: This is the UV to the Object below. It has medium amount of shells, but still enough to make it inefficient to do the layouting by hand, considering taking care of shell padding. Or is it just me being inexperienced?

poopipe

You're not wrong.. An auto layout will be much faster 

If you're happy to not share texture space and aren't having to account for LODs or heavy mipping  then I expect those UVs will be fine

 if you have a tiny texture budget and LODs to worry about then an auto layout is very unlikely to be optimal and that's what happens when you're making a wheel for use in a game. 

NealAdamLT

poopipe said:

You're not wrong.. An auto layout will be much faster 

If you're happy to not share texture space and aren't having to account for LODs or heavy mipping  then I expect those UVs will be fine

 if you have a tiny texture budget and LODs to worry about then an auto layout is very unlikely to be optimal and that's what happens when you're making a wheel for use in a game. 

@poopipe Since I haven't worked with LOD's yet, but will do in the future, texture Mip's will be needed. What is the problem with auto layouted maps in comparison to normal ones for MIP's? Shouldn't the only problem be to less pixel padding between texture Islands (which I took into consideration (2k Map = 16 Pixel Shell Padding))?

poopipe

LODs and mips are separate (but not unconnected) 

its usually wise to put parts of the object that are similar colours near each other to minimise the impact of mipping at large view distances (that said, if you're padding that much you should be ok) 

LODs affect your UV layout a lot  as you need a split in your geometry for every shell - it's hard to illustrate without a picture but you tend to end up with more efficient and better looking LODs (manual or simplygon) if you consciously lay out UVs so that large areas of geometry can be flattened to a plane. 

eg. if you were making a cast iron gate, it would LOD better if you planar map the front/back faces and lay out the perpendicular faces off to the side somewhere - that way you can drop it to an alpha tested  box with virtually no visual impact .  If you mapped the whole thing using strips you'd quickly find yourself with a pretty crappy looking gate that still used a lot of geometry. 

NealAdamLT

poopipe said:

LODs and mips are separate (but not unconnected) 

its usually wise to put parts of the object that are similar colours near each other to minimise the impact of mipping at large view distances (that said, if you're padding that much you should be ok) 

LODs affect your UV layout a lot  as you need a split in your geometry for every shell - it's hard to illustrate without a picture but you tend to end up with more efficient and better looking LODs (manual or simplygon) if you consciously lay out UVs so that large areas of geometry can be flattened to a plane. 

eg. if you were making a cast iron gate, it would LOD better if you planar map the front/back faces and lay out the perpendicular faces off to the side somewhere - that way you can drop it to an alpha tested  box with virtually no visual impact .  If you mapped the whole thing using strips you'd quickly find yourself with a pretty crappy looking gate that still used a lot of geometry. 

Ah, now I get your point. Thanks a lot for explaining I think I am going to read a lot about LOD's and how they are generated, to better understand how to lay out UV's for better LOD's. Do you have any references so I can better understand how to make UV's better suitable for LOD's? Since like you already said, it is pretty hard to visualize without a picture.
And thanks again for your help!

poopipe

The only decent images I've got are for work and I can't put them on the internet without getting told off. 

The best thing to do is make the LOD before you do UVs. 

A good, simple example is an I-Beam girder.  The top LOD will have the I profile, the bottom LOD will be a simple box. 
Lay out the UVs for the lowest LOD and then place the top LOD UVs over them so they match up.  Any extra shells are then placed wherever they'll fit. 

NealAdamLT

poopipe said:

The only decent images I've got are for work and I can't put them on the internet without getting told off. 

The best thing to do is make the LOD before you do UVs. 

A good, simple example is an I-Beam girder.  The top LOD will have the I profile, the bottom LOD will be a simple box. 
Lay out the UVs for the lowest LOD and then place the top LOD UVs over them so they match up.  Any extra shells are then placed wherever they'll fit. 

Thank you once again for your explanation. I think learning by doing is the best you can do for that kind of stuff