What's the trick to UV Unwrapping?

Hello there, if you’ve been in the modeling topic recently you have have seen me making a Dragon like creature. I know that making that post has made this dragon look far better than it would have if i tried it alone d:

And so here i am in this topic wanting to ask if any of you have any tips on UV unwrapping. I have always had a hard time with it and still continue to do so. I was watching parts of the Piero course on Blender cookie for information and i was inspired by how amazing the bump map painting was that i feel like would be a real Gem to have the knowledge to do it. To do that you need to UVUnwrap the creature first. Also in the Piero course i was watching the unwrapping video and it seemed like the best sort of seams would be (The dragon is a Wyvern by the way so it’s alot like a bird) would be to start with a seam staring from the middle of the forhead, and extend it all the way down the back to the tail, and then underneath the tail to between the legs. Then from there choose a loop on the legs as a seam and connect it to that first one. Along with that it would be good to have a seam from the loop around the leg to go down and under the foot aswell as seaming off the toes/talons. And then do the same with the arm as the leg.

Anyway whenever i unwrap it creates the craziest proportions along the UVs… 2 faces will be half the canvas on the tail, while the entire head is incredibly small and the top of the head with the eyes is far smaller then the bottom jaw.

Anyway, i’ve just always been pretty terrible at UV unwrapping and i wondered if you all had any tips or answers to what you use to struggle with in UV unwrapping.

Thank you so much T^T

Here’s the dragon by the way. 2 legs, long body, arms are part of the wings and what not. it’s about 3,000 verts after the mirror modifier.


It’s like reverse tailoring. instead of making a flat pattern into a 3D object, you’re making a 3D object into a flat pattern. Another way to think about it would be skinning an animal. you want the pelt to lay out flat, so you make cuts in a way that it won’t bind or pull at itself when you lay it flat. but don’t get the idea that it needs to be all one piece. with the current texture painting code, the number of pieces doesn’t matter so much. the main thing is to make sure all protrusions have enough seams, or they will distort. so if you unwrap a finger, for example, make sure there’s a seam along the base, separating it from the hand, and also a seam along the length, so it can unfold easily.

the uv distortion sounds like either Ngons in your mesh or disproportionate scale. fix the scale in object mode by pressing ctrl a and select scale. fix ngons in edit mode by making them quads.

for the seams i would cut off the horns and head (with a seam, not physically!), and split the horns right down the back and split the head from the fore head.
i would consider how the model will be posed and if mostly the back is showing, cut a seam down its belly. or if its belly was showing mostly, cut the seam down its back to the tip of its tail.
then cut off its legs and split them down the back also i’d cut off its wing and split it along the back skin edge. i may cut off its talons to and treat them the same as the horns. you may need a large image to texture it to, 16k most likely or seperate the uvs into sepreate uv maps, but you may get issues with seams showing up there

When you have parts of your mesh that UV unwrap into tiny tiny bits, grab a couple of known vertices (say, corners of the mouth) and move them apart and pin them in the UV editor. Then unwrap again. The UV unwrapping algorithm will take those pinned verts into account. You may need to do this more than once, but when you have verts where you want them in the UV editor, pin them so they stay put.

Another trick is to only select part of the mesh, say, the top of the head, from the upper lip up to the horns, and just unwrap that. Once you have the top of the head spread out like you want it, pin it, select more of the body, and unwrap that.

I like alot of what’s being said here and the Unwrap really is starting to improve.

I think i’m either going to have to just redo the head… or try and separate it into many pieces.

I really liked that UV pinning. I didn’t know that was an option before and it’s really nice d:


Orinoco, want to add my thanks for that tip on pinning. :slight_smile:

I don’t know about the latest versions, but there’s a feature called ‘live unwrap’ that allows you to optimize it in a similar way, but you can see it in real time as you move a pinned UV node.

I think i have managed to get something that is paintable on.
Somehow i got it to unwrap so that the head was unwrapped with the mouth being wide open in the middle. I tried to put a seam down the middle of the head to the nose and another down below the jaw hoping that it would unwrap like i pulled the jawbone out from the back on each side (or lick unfolding a row of teeth so it’s all in a straight line)

but somehow i managed getting this. the sizes were still far off, but with a little proportional editing i managed to tweak it a bit safely to get this result.


The head is at the top left.
i also fixed the body in the middle with that proportional editing. It was very large on the right and very small on the left.

So to see if i can paint on it now i’m using a 2048x 2048 image. (someone mentioned a 16k image but… i wasn’t 100% sure what that meant… like, 4,000 x 4,000? )

mouth area looks a little awkwardm ake sure noe of your uv faces are ovelapping or yuo’ll just be painting the same image onto two seperate parts of the mesh. 16k image = 16384 x 16384. for a model of your complexity and size ,having thw whole model sharing a 2k image map you will find that it looks very low resolution. especially on the wings, as you have them now, they have the space of aproximatly a 512k image ( maybe not even that)
i’m sure there are some issues in your mesh, you should get a better unwrap than what you have so far.
apply a test grid to your model so you can see the issues you may face once you start painting. stretching, different size areas overlapping etc

Hmm, i tried putting up the UV Grid with Live unwrap on, and my mesh just turns black for some reason. It will display the other thing i was already painting just fine but it doesn’t seem to want to show the UV Grid.
And you are right that i may want to redo some thing. Painting on the head was going alright,but my problems are that the flaps of the wings were flat planes. I thought that if i painted a texture on them it would just display the same thing on both sides of the plain, but it seems that actually the underside of the wings becomes invisible…
And then the other problem is around seams there was something strange going on.

For the most part it was happening around the lengths of the skin from head to toe. I would paint on the mesh itself and the colors would shift around real strange. I looked at the image that was being painted in the UV Layout and it seems the paint is placed a bit offset from what i was painting on the mesh. I’m probably 90% sure there’s some sort of User error going on here but i do find it puzzling. Although if i painted around the seams in the UV Image Editor it would work just fine. I’m just worried that if i move onto painting with bump map like stamps like in the Piero tutorial that the stamps will have the same problem.


I don’t know if anyone wants a hands on look at the model. i’d hate to bother you to feel obligated to look at it, so this is just if you want to see it d:

Attachments

RandomKnightWyvernMonster.blend (1.84 MB)

It would be better if you were able to adjust the UV islands so that it covers most of the UV area. In the current form you’re wasting more image area than what you’re using for painting.
Other things to consider:

  • Keep UV island size relative to other UV islands (ctrl+A to average island scale in UV/Image editor). That way your texture pixel (texel) density doesn’t change from area to another. If you’re changing that conciously, that’s fine, not all areas need as many pixels.
  • You can assign multiple images for the UVs to paint to, if that makes things easier for you

Here’s a quick tutorial that might help http://www.youtube.com/watch?v=EIMJxX9i490

for some reason I am getting crashes both when opening the blend, and even when I appended the dragon.

Hmm… Well to be honest, i’ve never actually uploaded a blend file on here before so maybe i didn’t do it right x:

I gave the textures a fake user and then saved the project. and when i tried to attach files using the attach file option, i didn’t exactly know where the file went when i uploaded it. Then i thought maybe i could just drag the file from the folder into the next line in the text box and that seemed to get the button to pop up.

But other than that i’m not 100% sure what the correct method to do put a blend file on here is x:

That looks really interesting. So i could use this method to have a different texture image for things like, one texture for the skin, one texture for the horns/claws, and one for like the wings or something?
I would also imagine that this method could be used to have certain islands have a larger size of texel density… I’m not sure if that explains that well but in other words, instead fo trying to cram them all together like a puzzle, i could have certain islands just have their own full texture image to maximize the detail that could be painted onto them?

Texture images created/modified in Blender have to be saved to the disk separately from the .blend file. Image menu -> save (as).
If you want to pack those in the .blend for upload, here’s how http://www.blenderartists.org/forum/showthread.php?311226-How-to-pack-texture-with-blend-file&p=2477297&viewfull=1#post2477297
There’s also compress option in the file -> save as dialog, so you don’t have to pack the file separately to make the file size smaller.

When you upload an attachment, it shows up like that when the file is listed in the attachment dialog. You could also choose to set it inline so that it goes in the text instead of attachment box, but either way is fine for .blend files.

(Can’t help but notice you having 1,337 posts* )

Alrighty, so i have used those methods to pack the images into the file. There was one that said it wouldn’t save changes on images that were painted on. So i’m not sure if it’s not saving the paint at all or just some of it. either way i didn’t doo too much. Just mostly colored the underside of the dragon white.

When i try and attach the file in the attachments i’ll upload it and it says it finishes but doesn’t appear in that list of things i’ve previously used.
I’m not entirely sure how i got that attachment box to even show up last time. is there a file size limit? that last one was 1.8MB and with the images packed in it it’s 2.6Mb

ok i UVed it to an 8k grid, its not an amazing unwrap as you have triangles and many many poles, but you can paint it ok.
if you want to reduce the size of the image thats ok, just assign a new image, no big deal the uv’s will scale appropriatly to fit, theres just that resolution issue again if you do that. also i had to pull some verts on the tail to fix some folding in the mesh while i unwrapped, but you can put those back yourself no worries.

Attachments

RandomKnightWyvernMonster_UV.blend (1.84 MB)

bwahaha! that’s nothing compared to my 14,463 posts :evilgrin:

Thank you so much! :smiley:
This looks much better than the results i was getting :smiley:
I tried to keep the triangles to a minimum but i do believe there was one or two. as far as poles go, i never knew a better way to have a high poly object like a head or a hand connect to a low poly area like the neck or the arm other than taking the loops of the geometry and use pulls to turn them so that they reverse back into the mesh leaving less vertices on one end than the other each time i do so.
someone gave me this image once to help me understand how to make a transformer per say to attach high poly areas to low poly.


So, that’s why there was alot of poles, because i didn’t know how to get more geometry in the head otherwise without really cluttering up the entire mesh.

But trying to understand how you fixed the Unwrap other than having the average island scale, did you really change any of the seams around to get the mesh to unwrap that evenly? I think i see that you removed some on the underside of the tail which in hindsight is actually a great idea to get the body to unwrap to be flat as one island rather than two similar islands like i had it before. But the head looks perfectly even in how it’s UV’s are laid out (:

bwahaha! that’s nothing compared to my 14,463 posts :evilgrin:

I am quite jealous of that xD whenever i see you post anywhere i definitely recognize you, what with that picture too xD
lets see, you’ve been on here for a little over 10 years so that means you post about 1,447 posts per year xD
You must be a genius to be able to be that helpful around here xD

1337 is a special number, Modron…