Question:jacket-uvmapping in blender

[Emily1313]

i finished making a mesh jacket but cant figure out uvmapping on it , its driving me crazy lol, if anyone has any advice on how to do this please let me know ty in advance!

 added note: im new to uv mapping and mesh, sorry forgot to add that.

ps ive watched tons of tutorials on uv mapping but im just not getting it....if anyone has some hints im all ears thx!

[Chosen Few]

Are you already familiar with UV mapping in general, and just looking for some strategy advice on this particular model, or are you brand new to UV'ing, so you need a biginner's guide to it?

If it's the former, then I'd suggest cutting the seams similarly to how they would fall on a RL jacket.  Cut the arms at the shoulder, and map each of them with a cylinderical proction, with the seam running down the inner length.  Cut the torso into front and back setcions, and use a planar projection for each.  Tweak a bit for best pixel density uniformty, and you should be good to go.

If it's the latter, then probably none of what I just said made any sense to you.  In that case, I'd suggest you check out the Intro to UV Unwrapping video on Blender Cookie.

[Gaia Clary]

It is basically like Chosen already wrote. And yes, i also would tell you to go to blendercookie first. Here is a short description for how the process for blender would be:

 

Mark the seams:

 

1. goto edit mode
2. select the seams (you could use edge select mode) . My first approach would be to identify the seams as they would be made for a real jacket.
3. mark the seams using CTRL-e -> mark seams  You can work seam by seam, and you can even add edges to exisitng seams if you missed some on your first try.

When you are done you have sort of "cut" your jacket  into "parts" .  Note that you do not necessarily NEED to use closed seams, but in most situations cutting your object into separate parts makes unwrapping easier. Sometimes it makes sense to add a split seam. You will do this sometimes to avoid distortions on the textures. think of your cloth would have to be stretched too much, or get wrinkled in a real clothing. I found that knowing a bit about sewing in RL helps a lot

Unwrap:

 

1. go to face select mode (not necessary, but helpfull)
2. deselect all faces of your model
3. Now Pressing "u" twice will unwrap your jacket. You may get a good result in fiorst place, but mostly you have to do some reworking. Mostly because of the seams might become problematic. The UV image editor is where you can tweek the UV faces.

Partial unwrap:

Sometimes it makes sense to unwrap your object sequentially. You would select one part at a time, unwrap it until you are satisfied, then proceed to the next. Although this may be a bit of work, it can give you better results. Mostly it makes sense to start with a full unwrap, then decide where to add more work. In general yo will work with the UV image editor to optimize your UV Maps.

The general workflow is:

 

1. goto edit mode
2. hover the mouse over the first "part" of your jacket.
3. press the "l" key (the ELL-key)  to select the part (works only if the part is fully separated by a closed seam)
4. Press "u" to open the unwrap selector)
5. Pess "u" again. This gives you a useable unwrapping of the part in most cases. Sometimes you need to do manual reworking. Alternatively use cylindrical unwrapo where appropriate. the arms loo0k like good candidates for cylindrical unwrap. Note that you must get into a view angle where you have a true sideview on your "cylinder". In your case front view seams good to me.

 

[Emily1313]

ty so much for the help, i tried the steps, cutting the jacket as a rl jacket and placed in cylinder mode. I placed a marked seam on top of the arm from neck to shoulder, then marked a seam around the arms, then marked a seam halfing the sleeve underneath it and side of jacket.

the jacket is fine except for the arms they are all stretched textures how can i fix this? ty:)

[Madeliefste Oh]

You did not cut the jacket in enough parts. You want the arms as different parts, at least two: both front arms and both back arms. Or even as four part: right front  and back arm, left front  and back arm.

[Chosen Few]

To answer your question about why your texture is so elongated on those sleeves, there can only ever be one explanation for that effect.  The UV layout for those areas just simply isn't wide enough.  The tighter the UV spacing, the less pixels you can have in between the vertices, so the texture gets stretched.  The wider the spacing, the more pixels fit in between, so the texture narrows.

Generally speaking, good UV'ing is about acheiving uniform pixel density across all the polygons in your model.  Faces that are large on the model should also be large on the canvas, and small faces on the model should be small on the canvas.

I went ahead and created a similarly designed jacket, to show you how I would UV it.

Notice I split it up exactly as I earlier describred.  In the upper left quadrant is back of the torso.  In the lower left quadrant are the two parts that make up the front of the torso.  Along the right are the two sleeves, each cylindrically unwrapped. 

The saw-toothed shapes in the middle are the three buttons.  They're each just 12x4 spheres, with the bottoms cut off.  The default mapping on those was fine, no need to remap.  However, if you'd rather work with orb-shaped maps instead of the grid-shaped maps, that's easy enough to do.  The pixel density per face won't be as uniform, though.

 

Note:  I made this model very quickly, just for demonstration purposes.  It's not quite 100% ideal, geometrically.  The poly count is a little higher than I'd like it to be, and the arrangement of the edge loops could be a bit better.  I formed the basic jacket shape in about five minutes, spent about half an hour or so tweaking it to get the edge loops flowing in roughly the right way, and then the UV'ing took just a minute or two.

 

 

[Emily1313]

WOW! ty so much!!!! i so appreciate you doing all this to help me!  This is very help ful and i made seperate arms already . which is a start:) And ty also to everyone else for giving me good tips on uv mapping!

[Chosen Few]

You're welcome, Emily.  Keep us posted on your progress.