So @Piotr_Adamowicz suggested I review the B Guru tutorial on intermediate UV mapping (which I’ve done) but I’m still a bit lost. I’m trying to UV unwrap multiple components of the room to one texture for baking and Unity import. Here’s my workflow:
- I’m unwrapping everything separately using smart UV unwrap
- I join all objects
- I create a smart UV unwrap of the joined
- In the material nodes I set two UV map inputs per material (Old UV and Join UV)
My problem is getting things to fit well on the map. If I select all and re-pack, it spaces things out poorly.
Any suggestions on seams for the baseboard/doorframe/handle/walls/ etc? I’m pretty confused and the best way to unwrap the seperate / joined objects to make a good use of the UV combination for baking out to the game engine.
Don’t use Smart UV unwrap. Manually add seams to every object.
As for spacing things out poorly, the pack algorithm is meant to give you a good start, but then it’s time to go in and move the islands around manually. There’s also addons that might do a better job, like UV Packmaster, but nothing beats a human brain 
You would also benefit from moving to Blender 2.8 because it allows you to edit and unwrap multiple objects without joining them.
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Hey thanks for the reply (again 
)
I understand how to make seams and unwrap, but I guess I’m just a little confused on where to make the seams. For example, where would you make the seams in this baseboard?
Unwrapping a box is easy, but the baseboards of the room are like 4 rectangular tubes glued together! Can you give me a sense of how you would unwrap something like that? Should I select every face and say unwrap one at a time maybe? My goal here is to optimize so that later when I join and smart UV unwrap the whole thing they will fit together better (this is how it’s done in this tutorial: Baking Multiple Textures onto One Map | No Plugins
I assume if I make better individual UVs before I join and make a joined smart UV it should pack better.
Maybe I’m better off looking at the Atlas? I also bought the ‘Bake Tool’ from the market but haven’t been able to make it work.
p.s. I managed to scale down some UV islands (as you said, to 0) and made the floor bigger, but still the wall is like one 10th the widths of the texture (see image) so very low rez.
However, I’d leave out the bottom- and wall-facing polys out of the texture. I might also split such a long baseboard into several sections of equal length.
Like I said several times, and like Andrew said in the unwrapping tutorial, do NOT use smart unwrap.
No, it will not. Smart UV will destroy your unwrap. After you’ve unwrapped each object individually, average the island scale and just pack them together.
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@Piotr_Adamowicz
Thank you for creating the geometry and marking seams to show me. I really appreciate it.
I will try your advice this evening and not use any smart unwrap 
I just noticed your earlier comment about 2.0 too, I will download tonight.
Thank you for your patience with a Blender beginner. UV wrapping is a major challenge but I’m happy to learn it!
Hey @Piotr_Adamowicz
Good progress!
I followed your advice and did not us smart unwrap for join, and things look better now (see image)!
Quick question. To make it simple, each object I selected all edges and marked seams, so every face was an island. I know this is bad if I want to apply texture, but is there any bad reason for that if I’m just baking lighting etc?
Also, is .03 an OK margin for my pack Islands setting?
Well, margins waste texture space, and if every face is an island, you waste more of it. Other than that, no, there’s nothing terribly bad about it.
Probably. But I don’t really know. That depends on the resolution of your lightmap, your engine, your mipmap bias, etc. Follow the advice I had linked for you here: http://wiki.polycount.com/wiki/Edge_padding
In general, the best way to find out is to just export it to your game and see if it looks ok.
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OK sounds good.
Thanks again for your help over the last few days.
Really nice community here in Blender. It’s why I came over from the Autodesk products.
