Official [2020.1] New Feature - Auto Pack Margin

Cool. If I understand correctly it's only an option if you're completely generating Lightmap UVs.

Since the unwrapping of lightmap UVs leaves a lot of things to be desired, could we perhaps have a hybrid method that takes user authored islands and just does the packing with the new margin stuff?

I have given up on Generate Lightmap UVs and getting the margins to look correct with hand authored UVs is kind of a pain, so it would be nice if we had tools to help with that too.

 

@AcidArrow that option makes a lot of sense indeed. CC @rasmusn.

 

I have to say then, I'm slightly confused on the purpose of the feature.

"Generate Lightmap UVs" produces very inefficient UVs. It was an okay algorithm 8 years ago, and it's still largely the same. I can't imagine anyone using it for anything other than quick and dirty UVs in early development, since it wastes a ton of lightmap space.

(and I have to say, I don't know why Unity isn't more invested in improving their packing/atlasing stuff, there are a ton of promising projects around these days you could get ideas from : https://github.com/Microsoft/UVAtlas or https://github.com/Thekla/thekla_atlas )

So, while it's "nice" that "Generate lightmap UVs" has proper packing distances, it feels like the feature is wasted, since it's a polishing feature that is applied to something that people shouldn't be using for their final UVs anyway.

There are a ton of small lightmapping adjacent features that would be really great to have (storing lighting values in vertices, I believe it has been discussed for a decade almost now) and apparently, there isn't room in the roadmap for them, so it's frustrating that when we finally get something, it's somewhat... misguided. Or at least, that's what it looks like to me.

 

using Unity 2020.1.0a25.3171
using HDRP 7.1.8

Im sure a previous commenter also had this problem, but I think if you change the Min Lightmap Resolution setting in the advanced tab of the Generate Mesh UV's sub-menu to something higher than your current Lightmap Resolution in the Lighting settings tab, it bugs and stops you using your keyboard to change values in the lighting tab, you can still use your mouse to change the values, it requires a restart of the project.

 

@DoomPriestK If it's this : https://forum.unity.com/threads/2020-1-new-feature-lighting-settings-asset.832984/#post-5515801 then as you can see below my post there, it's an unrelated issue that hopefully be fixed soon. (you can track it here : https://issuetracker.unity3d.com/is...-keyboard-after-switching-between-editor-tabs )

 

Hi @rasmusn , your statement brings up my years-old problem/question regarding the Unity "baking" process:
is there any workflow that allows imho quite logical option - to use the UVs generated and imported together with the 3D object itself - in an external DCC application (3DS Max for example), most of which have far superior unwrapping algorithms and provide much better control over it?

There is somewhere here years-long forum thread discussing and begging for such option as the current Unity UV unwrapper is really really bad and ability to use imported well-optimised UVs would most probably clearly outweight all the benefits of the feature you have "advertised" here...
One of the topics discussed there was also - if we try to generate the unwrapped UVs for baking externally - which UV channel should be used as it seemed not quite clearly mentioned in the Unity documentation... is this clear now?

 

Thanks for this! It's been one of my number one irritations if I'm honest, with Unity's lightmaps. I even have had to use dodgy lightmap scales to edge things into shape. So this is a big improvement, possibly more than most people realise.

What remains, I think is to improve lightmap resolution consistency where there are a lot of separate lightmap surfaces. Unity seems to struggle here, with some objects sharing, sometimes waste space sometimes it just has poor results but AFAIK that just is a whole different kettle.

Is it available for Bakery / Other lightmappers? I guess so providing it uses only Unity's lightmap UVs.

@guycalledfrank any thoughts?

 

AFAIK bakery already adjusts padding plus other stuff. It doesn’t need this.

 

Well in any case, if the upcoming feature is good enough for Bakery to use, maybe they can start using it and free some dev time for other features.

 

Packing by group will be a nice feature to implement to!! so my chair in room A will not be on atlas 31 with room Z

 

Yes! This was exactly what i was thinking when I read the paragraph. Please unity devs! That would be an amazing feature

 

I understand @AcidArrow's sentiment completely. It's not entirely "wasted" effort, but the effort should be expended on dealing with more important issues at hand..i.e. the poor packing algorithms for generating UVs. I've been a user of Unity for over a decade and to see that a decent auto UV algorithm hasn't been developed within that time frame is disheartening. So I understand what he meant. Who cares about pack margins when the UVs themselves are terribly wasteful. We're talking about facilitating millions of developers to produce games and products that will ship out into the world with poor memory management...or rather poorer than it needs to be out of the box. Why not focus on empowering developers to manage memory more efficiently? Versus continuing down the path of ignoring the problem of wasteful texture memory utilization?

PS - As an aside, did Unity ever get in that functionality for passing through user-authored lightmap UVs without repacking them, shifting or moving them around on atlases? Basically pass them directly through not altered in any way...how it was done in Beast.

 

Rasmusn - thank you for the information! it´s 2019. feature very cool.. I still in the 2018LTS so not deep familiar with a lots of hidden new features!! really nice to know!! the next game will be 2019.3... this one for quest i will keep on 2018 until we release the update!
cheers!

 

Hi,
Reviving the lightmapping thread a bit...
the "Generate Lightmap UVs" checkbox is very handy, sure it makes ugly UV's on "soft/organic-like" meshes, but still. It's a One click feature that let's you bake any objects pretty efficiently. not overlapp, no unfolding hassle...
and I still author my own UV2s when necessary...
So auto pack margin feature, yeah that's cool. but the feature that changed a lot the final quality for me on Automatic UV's is the Stitch Seams option couple years ago.
Now even with poor UV2, the final result is very decent (in terms of quality, now memory waste on lightmap is another story)
I baked this helico interior a few months ago (see image) with GPU and Automatic UV's, and it's fast and clean... while a few years ago it wouldn't have been that easy.

Now about a pass through option
There used to be a Lock Atlas feature with Beast back with Unity 4.
and it was possible to force bake the lightmap within 0 and 1. no offset, no tilling.
I'm trying to reproduce that on a project right now... and I still get some tilling no matter what. also padding is 2 as a minimum value, tried editing that padding value manualy in Lighitng Setting file, doesn't seem to take.
My goal is to bake some lightmap in Unity for specific animated objects and use those lightmap in the shadergraph to lerp between 2 states or more. to have Animated Lightmap. and right now I'm a bit stuck...

@rasmusn
I've been using Unity for almost a decade, and I'm now really happy with the Auto Generate Lightmap UVs and the actual, pretty robust, GPU lightmapper !

 

I've tried a workaround to solve my actual problem :
I have several objects I want to bake in one single Lightmap, onto my prepared Layout, to be used in a shadergraph later.
So I combined those objects to have one single Mesh for the bake, to bake lightmap on the layout without any repack by Unity.
But I was still ending with some small offset and tilling like mentionned in previous post.
The workaround :
I added some cubes to the combined mesh, really small/invisible, just to have UVs present at the four corners of the layout.
So Unity detects my layout as a full 0 to 1 UVs and it doesn't apply any offset or tilling on that. (see attachment (this is a test, UVs are "auto-layout" in Maya))
It's kind of a trick more than a real process, but maybe it can help other people.

 

Maybe you guys should pin this thread

 

If I understand correctly, this will generate UVs for the whole scene at once, so packing will be more efficient since you're getting rid of the requirement of having a mesh UVs be their own little box and then having those boxes packed together.

That has the potential to work well, but can you please make sure if this feature ever sees the light of day, that there is a mode where we can supply the UV islands ourselves, and then your algorithm can move scale etc them as it sees fit?

Even if the new UV generation algorithm is great, being able to control where to have or not have seams is a must have and the simplest way for this would be for the algorithm to accept user authored UVs as input and then repacking them.

 

Also, looking at that linked PDF, this is a feature that would be useful for Unity and potentially an easy-ish implementation?


At the very least it would make it easier for people on the forums to explain why their lightmaps look weird, but it would also be useful for lightmappers to identify potential errors (I generally never use double sided GI unless I have a very specific reason). It could be a debug view in the scene view.

 

Hi, I'm updating a project (from Unity 2019 to 2020) which had several levels with light baked and autogenerated UVs, when I open the project with the new version it recalculates all auto UV's and now my lights are all broken, Have you anticipated this? is there a fix that doesn't involve baking all of my levels again?

 

Wow! How I missed that. Awesome feature, indeed. Congrats!

 

Any news about this feature? Unity should be able to just use the imported UVs and repack the individual UV islands with an adjustable padding. This would make lightmaps much more efficient and save a lot of time.

 

In Unity 2021 its not working.
This packing is terrible.

 

Start a new thread and post more information, the packing is generally still pretty bad, but this feature generally works, from that image I cannot tell what the problem is.