Blender UV Unwrapping, pinning, pack islands....

[Anna Nova]

Following the advice I got here about UV Unwrapping, I am now trying to optimize the UVmaps.

I am not understanding what I read in the Blender manuals.

I unwrap, and get a nice even UV Map.  But it has waste space with plain areas that are duplicated, so I edit the UV map to put them over one another (thus they will receive the same texture), and to stop blender moving them I pin their vertices.

Now when I unwrap my reading of the manual says blender should leave those vertices alone, and it does.  It totally ignores them and maps other stuff right over the top!  Gaaaaaa!

So, I think: don't unwrap again, use 'pack islands' to re-layout the map.  No!  That ignores the pinning and moves the nicely layered faces to their own space.....  Gaaaaaa!

What am I doing wrong?  (I tried googling, but clearly I am not aware of the correct vocabulary)

 

[Love Zhaoying]

Unwrap is like unbox?

 

[Anna Nova]

52 minutes ago, Love Zhaoying said:

Unwrap is like unbox?

Now I know how you got to 2000plus posts......

I need a new bye-line for when I get to 500.  How about Neko Lion Tamer.

[Pierre Ceriano]

The question is : "Why do you pin the vertices" ? Doesn't it work fine if you just let the duplicated islands together without pinning ?

[Love Zhaoying]

53 minutes ago, anna2358 said:

Now I know how you got to 2000plus posts......

I need a new bye-line for when I get to 500.  How about Neko Lion Tamer.

 

[Love Zhaoying]

I learn from these posts even though I know nada about mush.

[Anna Nova]

36 minutes ago, Pierre Ceriano said:

The question is : "Why do you pin the vertices" ? Doesn't it work fine if you just let the duplicated islands together without pinning ?

No.  This is the UVMap as Blender's 'unwrap' presents it:

 

Notice the 2 large and 4 small areas that are actually to be textured identically, so I move them to coincidence.  This was suggested by Aqila as a way to get some more texture real-estate for the details:

But as soon as I try to unwrap again, I either get back to the first picture or, if I pin the verts of the moved islands I get this sort of thing:

Notice that the pinned islands have not moved, but all the other islands have now been mapped over them.

Edit:

I suppose I could resize everything by hand, but I'm not going to do that as I have 11 of these to do, and life is too short,  I'll just import more 1024 textures and say "to hell with the lag....."

Edited February 28, 2018 by anna2358
see above

[Pierre Ceriano]

Indeed I see. I usually arrange by hand then and rescale the whole. But I'm also interested to learn a shortest way. Hope a more skilled person will answer your question. I will follow that thread.

[Rolig Loon]

I always do everything by hand too.  It takes at least as long as making the model itself, and I'm still not good at it.  It's hard to remember to keep islands rotated properly, scaled appropriately, and still get the best packing. I tend to unwrap the whole model first and then go back and attack specific islands individually -- unwrapping some by following active quads to get them square and others by projecting from view.

[Pierre Ceriano]

An other way is : gather all the parts that will have the same diffuse at the end and create those parts with the array modifier. Then unwrape before applying the modifier. You will have to arrange the "arrayed" parts maybe. The deal is to determine if it takes more time to arrange islands or parts...

[Chic Aeon]

OK. I hope this doesn't confuse things more but here is my input.  I don't ever pin (except by accident and now I know how to unpin so that helps LOL) and I never pack islands as I often touch up in my graphics program AND I like to be able to make sense of my UV map even if it doesn't make sense to someone else.

What MIGHT be of help would be "work flow". 

I typically unwrap as I go which saves lots of time especially on parts that will repeat.l When I have something that will be taking the same texture (AND LIGHTING - more on that later) then I have the piece already unwrapped. [unwrap the piece before making any copies of it. This also let's me see the texture on it as I am working.]   Here is a recent item and a further explanation. Note this is not THE WAY, just MY WAY and not necessarily suitable if you are mainly using tiling textures and don't care about the lighting and shadow part of the equation.

 

 

In this case I made ONE hook which would be repeated across the back of the stand. I unwrapped that hook (not bothering to straighten all the edges in this case but that certainly could be done).  I then used the ARRAY modifier to make enough of the hooks to span the back of the stand. All of the hooks are then exactly in the same spot. 

The boards I also mapped from the first board and then reused that same mapping (so not having to unwrap again) . I purposefully have a new space for each board so that BOTH the woodgrain will be different on the pieces AND so that the subtle shadows can show up (the whole point -- for ME -- of using cycles).  The brackets "could" have been mapped as a single bracket, but then I would have had to keep the bolts all at the same angle on each piece AND there is a subtle difference in the lighting there too.

So it IS all about choices. But thinking about WHEN to unwrap might be a good plan.  I almost always make up my materials as I go along also and work with materials on in the viewport.  Again, personal choice and I always textured prims at the beginning also rather than at the end. 

I am sure the really smart folks will come and explain how pinning works :D.  Note that you CAN unwrap just one material at a time OR even just one small piece (like a board) at a time simply by choosing that part (or parts) and unwrap. You don't have unwrap the whole model again. 

 

 

Edited February 28, 2018 by Chic Aeon
working on clarity :D

[Anna Nova]

Not that I'm not grateful for the suggestions, but they don't answer my question.  Before I commit to weeks of work to do it your way(s), I'm still looking to understand pinning.  As it stands it is useless, and I don't believe that for a moment.  I suspect I need to switch something on or off.

[Chic Aeon]

8 minutes ago, anna2358 said:

Not that I'm not grateful for the suggestions, but they don't answer my question.  Before I commit to weeks of work to do it your way(s), I'm still looking to understand pinning.  As it stands it is useless, and I don't believe that for a moment.  I suspect I need to switch something on or off.

Well from your example photo it seems clear that pinning keeps the items PINNED in place but doesn't affect anything else  . I looked up a few things on pinning and tried to figure out when it might be useful. From what I found it is mostly about keeping certain islands on a specific place on the UV map and of course it did just that.  This could be handy if applying textures inworld rather than baking.

I couldn't find any info saying that you can tell Blender to "work around the pinned area" so to speak, but perhaps that is possible and I will be interested to see that.  Basically most of us have found over time that it is better to "do it yourself" when mapping rather than to let Blender do it for you ^^. 

Good luck and I hope you find the answer you are looking for!!!!!

Remember that Blender is a huge program and is used in OH so many ways for different things. Pinning would have been very handy in Cloud Party where we were limited to very small textures and often had to put several textures on one texture plane in order to get them on objects in world. You could THEN tile the the textures in world if you lined them up very carefully on your UV map -- and with the texture you wanted to use later. 

 

 

[ChinRey]

I'm not sure if I understand the problem, Anna, but if you want to pack the islands as efficiently as possible and then have them cover as much of the UV map as possible and still stay in scale proportional to each other, what I would do is pack everything at the center of the map and then simply scale the whole thing up.

 

This is not a good example since this build really, really, really shouldn't use a single baked UV map but it's the best I could find in a hurry and it should illustrate the principle.

Make something like this:

Select all, make sure "Constrain to Image Bounds" is checked, snapping is off and you may want to uncheck "Snap to Pixels" and scale it up:

Until it covers the whole area give or take a pixel or three:

That's about it.

[Bitsy Buccaneer]

3 hours ago, anna2358 said:

Notice that the pinned islands have not moved, but all the other islands have now been mapped over them.

Edit:

I suppose I could resize everything by hand, but I'm not going to do that as I have 11 of these to do, and life is too short,  I'll just import more 1024 textures and say "to hell with the lag....."

I think that's normal behaviour. The pinned islands stay where you pinned them and then everything else does it's own thing, which results in overlap.

Looking at the 2nd map (where they're first overlaid), I can see two approaches to try. Both involve looking at it in terms of groups rather than dozens of individual pieces - which might just help with the life's too short aspect.

The 2nd map (where they're first overlaid) has a good bit of space around the edges where you can bulk move things to. There are two groups which could easily be selected and moved, one up (red) and one right (blue). There are a few bits which are candidates for being moved on their own (green arrows), though one of them could become part of the red group quite easily if you included the orange highlighted part. That would give you some nice clear real estate to use to enlarge the coincided bits if that makes sense for your build. I keep seeing them as large walls and the kind of thing which might work well scaled up, depending on how it's textured.

If they're not, and you want to keep each part in scale with every other part, just remember to do all your resizing with everything selected. I'd start by making it so the red group fits the full width and see how much room there was after. Eyeballing it, I'd guess that the blue group would be close to where it needs to be and the purple one moved to the right.

Does that get you any closer to a solution you're happy with? Fingers crossed  

[arton Rotaru]

2 minutes ago, Bitsy Buccaneer said:

I think that's normal behaviour.

Just another annoying behaviour of Blender at least.

4 hours ago, anna2358 said:

I suppose I could resize everything by hand, but I'm not going to do that as I have 11 of these to do, and life is too short,  I'll just import more 1024 textures and say "to hell with the lag....."

I'm afraid I am of no help either , but if these 11 means 11 of these walls, can't you just get away with doing 2 or 3 maybe, and just copy those around the build?

[Anna Nova]

31 minutes ago, arton Rotaru said:

Just another annoying behaviour of Blender at least.

I'm afraid I am of no help either , but if these 11 means 11 of these walls, can't you just get away with doing 2 or 3 maybe, and just copy those around the build?

I guess that may be the best plan.  Each of the 11 is different - there are 16 walls of 11 types.  But there are common elements, so I may be able to isolate those and so reduce the number different textures.  The problem is that the texture at High-LOD is what gives the detail to the Med-LOD (and thus also the Low and Lowest) so I have to figure out a better way of handling that.

 

44 minutes ago, Bitsy Buccaneer said:

Does that get you any closer to a solution you're happy with? Fingers crossed  

Yes, it does.  I only did the overlaying of the obvious large areas, thinking that a I could re-unwrap to improve the size of the smaller item and thus the detail they could carry.  I can carry on and fix the round things by making them straight, and overlay those, and several other significant items.  Then have a quick re-layout and scale-up.

This has been an excellent exercise, and thank you all for your thoughts.  I'll get there.....

[arton Rotaru]

37 minutes ago, anna2358 said:

Each of the 11 is different - there are 16 walls of 11 types.  But there are common elements, so I may be able to isolate those and so reduce the number different textures.  The problem is that the texture at High-LOD is what gives the detail to the Med-LOD (and thus also the Low and Lowest) so I have to figure out a better way of handling that.

I see. That's the problem with recreating RL builds as close as possible I guess.

Here is some inspiration of how the pros attack buildings in games these days. Don't be upset though, by how awesome this building is looking, and how cleverly it's built. It's an absolute masterpiece, and we don't even have all the features in SL to pull it off like that. But it might give some insight of how such stuff is done today.

http://polycount.com/discussion/184711/dishonored-2-environment-art-dump

Edited February 28, 2018 by arton Rotaru

[Bitsy Buccaneer]

4 minutes ago, arton Rotaru said:

Here is some inspiration of how the pros attack buildings in games these days. Don't be upset though, by how awesome this building is looking, and how cleverly it's built. It's an absolute masterpeace, and we don't even have all the features in SL to pull it off like that. But it might give some insight of how such stuff is done today.

http://polycount.com/discussion/184711/dishonored-2-environment-art-dump

sobs quietly

[Love Zhaoying]

28 minutes ago, Bitsy Buccaneer said:

sobs quietly

 

[ChinRey]

36 minutes ago, arton Rotaru said:

Here is some inspiration of how the pros attack buildings in games these days.

Wow, yes that is truly a masterpiece!

 

37 minutes ago, arton Rotaru said:

Don't be upset though, by how awesome this building is looking, and how cleverly it's built.

I think the first and fourth image on that page are key ones. I may overlook something but it seems to me picture no. 4 shows the entire set of meshes used for the building in picture no. 1. That's the kind of minimalism you need to make something like that for a dynamic 3D environment.

You also need those shaders of course and... well... that's not going to happen neither in SL nor Sansar in the foreseeable future.

[arton Rotaru]

9 minutes ago, ChinRey said:

it seems to me picture no. 4 shows the entire set of meshes used for the building in picture no. 1

Yeah, further down in the thread is a higher res image of these modules even.

10 minutes ago, ChinRey said:

You also need those shaders of course and... well... that's not going to happen neither in SL nor Sansar in the foreseeable future.

Right, not going to happen in SL at least.

[Bitsy Buccaneer]

Just had a thought - the long thin ones in the middle that I gave a green arrow to as candidates for repositioning on their own - I think they might be a constraint on the scale. Try moving and pinning them elsewhere (top left corner maybe) and then unwrapping that 2nd map again.

[arton Rotaru]

In Blender 2.79 is a so called Magic UV add on included (has to be activated in Prefs), which might have some useful features like copy pasting UV shells. With that you could unwrap and pack everything but the faces that are supposed to be stacked, and then copy a UV shell, select the faces in the 3D view that are supposed to be stacked, and paste the UV coordinates on them.

https://blenderartists.org/forum/showthread.php?391573-Add-on-Magic-UV-v5-0

Also be aware, you will have to move the stacked UV shells by 1 unit out of the 0 - 1 UV space when baking.

It's also important to have some margin around each UV shell to prevent color bleeding on the mips in-world.

[Aquila Kytori]

On 2/28/2018 at 7:50 PM, anna2358 said:

I only did the overlaying of the obvious large areas, thinking that a I could re-unwrap to improve the size of the smaller item and thus the detail they could carry.

It can be sometimes usefull to think about the UV unwrapping at the same time as you are thinking about how to create the actual model.

Using the Mirror, or Array modifier and copy pasting parts can save time if you know in advance that you will be stacking some of the UV islands :

 

 

 

Organized UV's makes it easier to later edit textures in Gimp if necessary :