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VictoryX
12-05-2014, 05:51 PM
I know this is a recurring theme on the forums, but I was hoping to get some help. I'm trying to UV a bottle cap model and I can't seem to get it right on the outside and inside without it stretching. I just can't wrap my head around UV Wrapping. I can do extremely simple UVing, but anything semi-complex I just lose it. Does anyone have any tips or tutorials I can follow to help get better with UV mapping complex objects?

UVMAP

The top bit is the outside, under that is the inside and the bottom is the tops and bottoms.

http://i526.photobucket.com/albums/cc346/adjustvolume/UVMAP_zpsafd10464.jpg (http://s526.photobucket.com/user/adjustvolume/media/UVMAP_zpsafd10464.jpg.html)

COLOR
http://i526.photobucket.com/albums/cc346/adjustvolume/Strecthin_zpse0b8ab40.jpg (http://s526.photobucket.com/user/adjustvolume/media/Strecthin_zpse0b8ab40.jpg.html)

I get that you are attempting to arrange them so that each is a same size square and lay it out evenly, but whenever I try to do that I get to a point where pieces are intersecting and parts wont layout so that I can form even boxes. Maybe if anyone has some completed well laid out UV's I could take a look at to get a better idea of what I'm supposed to be doing.

tonyrizo2003
12-05-2014, 08:14 PM
Here is a quick model of a bottle cap that i did using catmull clark subd. I grabbed the top polys first and UV mapped them along the y axis, make sure that subdivision is selected and not linear. and then I inverted the selection for the sides except I used cylindrical subdivision on those and then double sided them. I hope this helps.
125869125870125872125873

djwaterman
12-05-2014, 11:10 PM
Here's one using ABF UV Unwrap and then a smidgen of point tweaking in the UV window to keep the outer edges circular.

125874

Surrealist.
12-05-2014, 11:17 PM
It also depends on if you are going to paint it or go with a 2D image map. Which are you planning?

VictoryX
12-06-2014, 12:06 AM
Dj that is a great idea. I had this vision of unwrapping the sides as a rectangle. But just basically placing a weight on it and flattening it would me much better! Surreal I'm working with image maps.

jeric_synergy
12-06-2014, 12:38 AM
I think what you want to do is make an endomorph where the geometry just makes a simple solid circle, just like a RW bottle cap is printed before forming.

Make your UV map from this endomorph, as just a Y-axis projection.

Having just tried it, I suggest you model two segments, covering the highpoint/lowpoint/highpoint of one 'crimp' cycle, do operations on that wedge, and then radial array it around to make the entire bottle cap-- I'm pretty sure that will save you work over lathing it.

Or, use HeatShrink.

sami
12-06-2014, 12:54 AM
VictoryX, I know this doesn't address how you do it in LW, but I feel compelled to say that UV mapping is sooo easy and sooo powerful in 3DCoat, that I strongly suggest you look at adding it to your toolkit. I used to have nightmares in LW UV mapping but now use 3DC and it's a piece of cake now. It is very LW friendly and you can easily edit your LWOs in 3DC and then bring them back to Modeler or Layout for further work. I've wasted so much time trying to tweak UV maps in LW that 3DC easily pays for itself on one project.

Unfortunately, until Modeler gets some love in development, using 3DC is kind of a necessity. Though that being said, your situation is easily handled by everyone's suggestions here - but if you do more UV, I'd suggest you check out 3DC - it's like Layout's and Modeler's long lost brother. ;)

Surrealist.
12-06-2014, 10:49 PM
My Version.

Took tonyrizo's object for sake of speed. Did not do this in LW for what it is worth. But it requires being able to define seems which I don't know how to do in LW.

125896

This is a configuration that will reduce stretching on the top of the cap. If all you need is color on the sides, and writing on the top it will work. But it is mainly a good UV map for painting. The other option as mentioned I think is makkng the side a cylinder unwrap.

jeric_synergy
12-07-2014, 12:12 AM
Dj that is a great idea. I had this vision of unwrapping the sides as a rectangle. But just basically placing a weight on it and flattening it would me much better! Surreal I'm working with image maps.
Well, this is ridiculous. I decided to take a look at ABF Unwrap, in the footsteps of DJ above, and with ONE, ONE click you get this:
125898

Literally couldn't be easier. DJ cleaned up the circularity, but he didn't stress how close you get with ONE CLICK.

This is using Tonyrizo's mesh. --Surrealist, I think you need to take another look.

Surrealist.
12-07-2014, 12:56 AM
Yeah I get it. But that method causes stretching. All of those unwrap methods do.

You see, deep breath, trust me when I say literally hundreds of unwraps later. I finally get it. The simplest way to put it is: if you can not make it out of a flat piece of paper, then there will be stretching. If you take a look at the UV map I made you will see that you could cut that out of a piece of paper in the real world and construct something very close to the shape. That is, and do it without compromising the structure of the paper - tears folds etc. All those places where you'd find you had to tear or fold the paper would be the places where you could solve it by making it into a new island and/or further cutting it. Similar to how packaging is designed, that when unfolded becomes one single flat piece.

Have a look at this.

125901

You see even on the open area here on the top where more than likely there would be writing, the image displays stretching.Or rather, you could say in this case distortion, caused by stretching.

UV unwrapping without a UV grid is a waste of time. You have to know where you have stretching. Some apps allow you to display stretch areas.

Even with relaxing and all of the tweaking you can do, you will still have issues that likely will never fully go away. It is far better to plan the UV so it will not stretch in the first place.

From there it is a matter of where you can have UV stretching and where you can't and where you don't mind having seams. It is a constant trade off that each unwrap has to solve.

When unwrapping use a UV grid like the one I provided. You can also find lots of them on the net.

tonyrizo2003 has a workable solution that used two logical projections. For his unwrap stretching on the top could not exist. However along the sides was more acceptable since it was mostly a solid color. But it would not hold up well if other mapping needed to be done on the sides of the cap.

My solution would hold up to baking AO and Normal maps as well as 3D painting on the entire object but also allow you to project an image from above without stretching the label. However my method comes with the draw back that having 2D image maps on the sides would be problematic. No stretching, but lots of editing in a 2D program to cover seams. Or you could heal (brush) the seams with a 3D paint app.

tonyrizo2003
12-07-2014, 01:05 AM
Wow this has been a very enlightening discussion on UV mapping!!

ABF one click is pretty crazy.

@Surrealist, you're absolutely right. Upon close scrutiny my mapping technique would stretch, and I would have to hide it some way or relax the hec out of it.

Thank you to everyone for sharing your techniques.

jeric_synergy
12-07-2014, 01:37 AM
It's been very educational.

Surrealist.
12-07-2014, 02:52 AM
Cool. Glad it has.

On this note, the Atlas type is also a non-stretch method. However there is no way to really control it, and it lacks options etc. Blender also has a similar tool. But in LW Modler you also have the old school trick where you can cut and past parts of the object to separate them before you do unwrapping. So with some forethought you can have more control.

Another thing to keep in mind is when you have repeating parts like in this cap you can UV map first and perform a duplicate spin operation. That can save a lot of time with tricky areas that take a lot of work.

djwaterman
12-07-2014, 03:03 AM
The stretching on mine is very minimal (ABF does it's own thing so it always depends on the object and how and if you designate a seam).

You can see on the UV image I made adjustments for the stripe on the side. If the top had to be absolutely perfect, I think I would do this type of ABF unwrap, then also do a tradition planer map on the Y, and edit those two UV maps into one UV map.

Yeah, I just did that and it works. So in this case with this sort of shape where the optimum type of image map would be like the print on a real bottle top that gets pressed into shape, using a combination of ABF and then Planer UV map for the top bit and edit the two together is a neat solution. But it's not a very complicated shape.

Surrealist.
12-07-2014, 03:31 AM
Yeah, thanks for the demo. Combining projections is another great technique indeed. I think I usually do a lot of different things to make the "Perfect" unwrap on a case by case basis.

djwaterman
12-07-2014, 03:47 AM
Bare with me, this will have to be a few posts because the forum wont let me do it in one go. But I thought it would be good to show the simple process visually and I didn't want to do a video because upload times take too long.

- - - Updated - - -

Continued.

jeric_synergy
12-07-2014, 12:30 PM
Another thing to keep in mind is when you have repeating parts like in this cap you can UV map first and perform a duplicate spin operation. That can save a lot of time with tricky areas that take a lot of work.
"Duplicate spin operation"??? Please elaborate.

+++ I know that ABF has "seam designation" features, but am #aflw currently.

JoePoe
12-07-2014, 01:08 PM
DJ, did you clear that section from map 1 before copying over from 2?

(thanks for the rundown :))

tonyrizo2003
12-07-2014, 01:19 PM
very cool, thanks for the tip!!

Surrealist.
12-07-2014, 02:30 PM
Great Mini Tut!

Another option to be aware of is the Texture Guide (Numeric Panel and "Make UV's" selected) allows you to make separate projections on the same map based on selection. There is also the Camera option which gives you other interesting options. You'd think that "make Uvs" allowed you to do this, I thought it did, but my version it seems bugged. Anyway.... very limited tools in LW native.

Been a Looooooong time since I used these:

http://homepage2.nifty.com/nif-hp/index2_english.htm

Others here are more familiar.

But what you need is a way to assign seams and unwrap based on the seams. Can you do that with the new UV tools in LW 11-2015?

Surrealist.
12-07-2014, 02:41 PM
"Duplicate spin operation"??? Please elaborate.

As in assuming you won't make changes to the model later and you have one part that will get a radial array... something like that or any clone operation etc. UV map it first and then duplicate will save a lot of time. Depends on what you are doing.

hrgiger
12-07-2014, 02:45 PM
If you want say text to go all the way around the bottlecap, you could also map it like this...

125928

125927

jeric_synergy
12-07-2014, 02:54 PM
125929

125930

125931

125932
I think those stray points were left over from a previous operation.

JoePoe
12-07-2014, 04:28 PM
Right... and to hrgiger's point.... this is what that "one button" unwrap would look like seam wise (my first ABF unwrap EVER!! :boogiedow)

125934

...And after about 30 secs of rotate and scale.... no distortion as far as I can tell (in Modeler)

125935

Yes, my bottle cap is oblong.

...oh, and Surrealist: Defining seams for ABF is just picking edges.

Edit: Whoops. Tried the actual cap. Interesting result using the same seam. I'm assuming it has to do with the unequal number/length of edges of that area, top vs. bottom. So I guess it's back to standard unwrap in that case?

125937

hrgiger
12-07-2014, 06:51 PM
Right... and to hrgiger's point.... this is what that "one button" unwrap would look like seam wise (my first ABF unwrap EVER!! :boogiedow)

125934

...And after about 30 secs of rotate and scale.... no distortion as far as I can tell (in Modeler)

125935

Yes, my bottle cap is oblong.

...oh, and Surrealist: Defining seams for ABF is just picking edges.

Edit: Whoops. Tried the actual cap. Interesting result using the same seam. I'm assuming it has to do with the unequal number/length of edges of that area, top vs. bottom. So I guess it's back to standard unwrap in that case?

125937

Yes, I got the same tapering result with ABF by trying to unwrap the bottlecap sides. The way I mapped mine was to take the ridged sides of the bottlecap, delete all but one of the sections, map it, and then radial clone it back around. Then in the UV, I just had to space them out end to end to give me the result I got above. This would all be made easier if we had stitching in LightWave UV mapping.

jeric_synergy
12-07-2014, 06:56 PM
If you'll notice in my 2nd pic above, I get a similar, yet less intense, spiraling effect. Not sure what's going on there, but a mechanical way to correct such effects would be welcome.

BTW, are there ANY dox besides the "What's New" on ABF? 'Cuz it's just a rather short paragraph.
+++++++++

My UV experience is limited (ha!), but what I think I'm seeing with ABF is that polygonal UV'ing is very close (if not spot on), but with subd there's a fair amount of distortion.

How does one compensate for the texture distortion of UV? It seems like that the "pie wedge" style of this object is contributing to the distortion-- if the logo area were a rectangular patch'd area would the subd distortion be lessened?

djwaterman
12-07-2014, 07:55 PM
DJ, did you clear that section from map 1 before copying over from 2?

(thanks for the rundown :))


I was expecting to do that but it turned out that the one map just overwrites the parts of the other which made it even less drama. What LW really needs is tools that allow you to edit the UV map in the UV view port (beyond move, drag, scale and rotate). This would allow you to use tools that bend or straighten things, relax or bloat areas, and I'm talking about a whole new tool set specifically for the UV window.

Surrealist.
12-07-2014, 10:04 PM
How does one compensate for the texture distortion of UV? It seems like that the "pie wedge" style of this object is contributing to the distortion-- if the logo area were a rectangular patch'd area would the subd distortion be lessened? It may, but this from my experience is from the pull outside of the wedge area. Think of it as trying to stretch a flat surface over a curved surface.

I can really recommend this as an exercise:

(I have done this and used this to teach artists about UV mapping)

Away from the computer, get some scissors and some paper. Take some random objects around the house/office and figure out how to make them from pieces of paper.

Something like perhaps this:

http://www.learner.org/interactives/geometry/platonic.html

or this:

http://www.instructables.com/id/Water-Bottle-Rockets-1/?ALLSTEPS

But it gets a tad more complicated the more complex the object.

Anyways if you can figure out how to cut it and make the object in question with single pieces of paper that you may later tape together, you will be doing basically hat you'd be doing to unwrap the object into UVs that do not stretch.

Once you get your head around this, you can start looking at objects as made up of primitives that unwrap a certain way to become single pieces.

Of course there is all kinds of room for compromise depending on the need. This is not an absolute technique. But it is the only way to completely reduce stretching. Relax tools can only do so much. So I find I balance it based on the need of the unwrap.

VictoryX
12-07-2014, 10:54 PM
I went the ABF route and I have to say it is easily my favorite tool now. As someone who enjoys modeling and texturing, but loathes UV mapping it works really well. I coupled it with PLG Relax and PLG Pack plugin and it worked beautifully. What took me hours to come up with a crap UV now takes me about 5-10 minutes and it works great.

COLOR Renders
http://i526.photobucket.com/albums/cc346/adjustvolume/BottleCapTop_zps89eeb9d0.jpg (http://s526.photobucket.com/user/adjustvolume/media/BottleCapTop_zps89eeb9d0.jpg.html)

http://i526.photobucket.com/albums/cc346/adjustvolume/BottleCapUnder_zpsdc315a3b.jpg (http://s526.photobucket.com/user/adjustvolume/media/BottleCapUnder_zpsdc315a3b.jpg.html)

UV MAP

http://i526.photobucket.com/albums/cc346/adjustvolume/UV_zpsa718bcc8.jpg (http://s526.photobucket.com/user/adjustvolume/media/UV_zpsa718bcc8.jpg.html)

I am ecstatic to find this tool knowing I no longer have to slap procedural crap on my models and hope it looks good.

tonyrizo2003
12-08-2014, 12:02 AM
Looks good, add in some normal mapping, a bit of spec and you're done!!

Surrealist.
12-08-2014, 12:09 AM
Yeah looking good. :thumbsup:

jeric_synergy
12-08-2014, 01:32 AM
Someone once said, if we actually advertised things like IKBooster and ABF Unwrap that are very underestimated, LW would 1) feel like a totally new application and 2) get a lot less badmouthing.

I say, add in some good Node Network Presets, and that's very very true.

And if scripting were just a tad easier (why was AREXX so easy???), well, it'd be a whole new ballgame.

hrgiger
12-08-2014, 02:47 AM
My UV experience is limited (ha!), but what I think I'm seeing with ABF is that polygonal UV'ing is very close (if not spot on), but with subd there's a fair amount of distortion.

How does one compensate for the texture distortion of UV? It seems like that the "pie wedge" style of this object is contributing to the distortion-- if the logo area were a rectangular patch'd area would the subd distortion be lessened?

Did you set your UV interpolation type to subpatch?

JoePoe
12-08-2014, 08:56 AM
Someone once said, if we actually advertised things like ...... ABF Unwrap that are very underestimated, LW would 1) feel like a totally new application and 2) get a lot less badmouthing.

And what would that ad look like.... I can just see it now...
Come on in and use our (in flashing lights) A-B-F Unwraaaaap!!
(Super fast talking voice over): relaxing, packing etc still requires multiple third party plugins.

It's a huge improvement to what was in LW, but still underpowered compared to what else has been out there ... for years. Unfortunately. :hat:

Uh oh, the ad caused more badmouthing! 8/.....:D

jeric_synergy
12-08-2014, 09:56 AM
::affronted aristocrat mode:ON:: "Invidious comparisons!!!"

;)

Damn market reality, always spoiling my fun. Still, seems slick to me.

hrgiger
12-08-2014, 12:31 PM
ABF is a fine unwrapper but unfortunately a one trick pony. To make a robust UV solution, we need things like distortion poly coloring, stitching, packing,edge straightening just to name a few...

The app UVLayout spoiled me.

jeric_synergy
12-08-2014, 03:36 PM
I suspect that there's some approach to ABF that works better than just jumping in blindly: some seam selection that makes things come out peachy, or possibly some endomorphing that would result in better unwraps.

But, it's pretty sweet for starters.

Surrealist.
12-08-2014, 05:16 PM
The UV Mapping tools in Modeler are outdated for sure.

The tools I use mostly however when I unwrap (in other apps) are the ability to assign seams, then unwrapping from that, and projections.

I have used the Zbrush automatic unwrapping tools with some success, but soon found it was still not giving me enough control.

Also I have used various relax type functions in other apps. But I have over the last few years limited the tools I find I need down to just unwrapping with seams, projection and manually packing. (Move Rotate Scale) I have not found any of the autopacking tools I have used to be sufficient. This is especially true when pixel space is at a premium and you need every bit of space in the map used that you possibly can. Mostly the Autopaking tools I have used do not take into account holes in the islands. If that was a feature it would make it more useful. Maybe some apps I have not used have that.

But basically, if you can just unwrap and plan your seams properly you can get real good results.

Cases where you can get a way with some stretching, the relax tools can help to a degree, but I don't try to depend on that and for the most part do not spend anytime tweaking after I unwrap. For me it is the best approach I have found. And then allowing stretching in cases where I can get away with it. Usually smaller parts or places, that have more organic textures (as in the final textured Grape bottle cap above) where stretching is not as noticeable along the sides.