Welcome to the introduction to marking seems in this video.
You realize that you've unwraps will have seams in them.
Well most of the.
Way you can do an unwrap where all the faces are on top of one another says all been squished together
into one location.
And of course that's useful for certain circumstances.
But usually you'll want to have seems to define how you want blender to unwrap will be learning how
to mark seams where you want them and understand that this gives us the most control over our models
unwrapping.
So we've said seems lots.
What is a seam.
Well it is a cut in your model telling blender how to unwrap the model itself.
Now if you imagine seem most of us would associate a seam with a bits of clothing now a bit of clothing
becomes a 3D model.
But essentially it's made from 2D fabric.
So it's a great way of visualizing how something two dimensional is then put together it's a three dimensional.
And of course the reverse if you were to unstitch along those scenes it your your shirt or your trousers
would end up being a flat bit of material.
And they may not resemble much of the original.
Close do look odd and so you ve unwraps occasionally it allows you to separate parts of your meshes
from one another and apply texture to those parts individually.
So a couple of tips for making seams and will go more into this later on as well.
Now seams can ease the cause distortion a mis alignment of textures so you do have to be careful where
you put them.
Seams often occur on hard edges.
Now on organic models that's not too much of a problem.
You just need to hide them out of the way.
But on a more industrial or what we call hard surface non organic models are hard edge and a seam often
coincide.
They are made where you are least likely to see them.
So if there is any distortion a misalignment of textures that you are applying you're less likely to
see them and they won't ruin your model and understand.
As I've said before this gives us the most control over our model.
So let's go make some seams now and hop on over into a blender.
Okay so we're going to start in a default blender scene and not try anything too complicated at the
moment when it comes to marking seams.
But I'm going to get rid of that cube and go ahead and add in a euv Sphere.
Now I'm going to play with that for a moment.
I'm going to give myself an image editor as well so we can see the unwrap as it happens we don't particularly
need an image there but if you want to play with the picture of the world that we were playing with
before then by all means go ahead.
Okay so let's have a look at what impact it has.
Why.
We just unwrap as we can expect it produces this.
Everything piled on top of one another and that has its uses but it's no good if we want to map something
across the entire sphere in this case.
So let's try adding in a scene.
Now what we need to do is select the edges or edge loop.
That's often very powerful.
Not always but sometimes.
I'm missing the edge loop here that goes all the way down from here to the very bottom and would just
start with that one and we need to tell blender that that edge is a seam and we can do that over in
the tool shelf and the shading Enu vs tab we can click on Mark seen is also available under the mesh
menu under edges Mark scene and of course we can see the shortcut for the edges menu is control and
so we can hit control any and Mark seam.
Now when you mark the scene it goes red in colour.
If I just.
Unselect that edge loop there we can see that it's red in colour.
Now select everything and see what happens if we unwrap and although it's different it's still a bit
difficult to use because of the stretching and distortion I can see in front of me.
So let's try perhaps adding in a nother.
Over the other side some with a hole down.
Old select the edge the loop running the other way.
It's not quite essential that select the other one.
I'm just going to clip Mark seam in the tool shelf.
Select everything and unwrap again.
Okay that's a bit different isn't it.
We've got to use V unwraps Now these because we've sliced all the way through the model they are now
separate islands.
If we.
Oh if I just expand this out so you guys can see more of the header bar down the bottom here.
Remember we can select the verte sees the edges the faces and then there's the Forth button there which
is Ireland.
We can actually move these individual islands about and if there was an image underneath it would be
changing on here as well.
Now we can add a seam around the equator of this sphere so that would be this one.
Here we go window control an E and Mark a seam and a select everything.
And unwrap.
How we get something completely different.
I think during that laskey press I must have accidentally created some doubles because we've got this
ring around here so I'm just going to select everything I'm going to search for doubles.
And remove doubles.
Yes I did inadvertently create a ring of double So let's unwrap that.
And that's created four separate islands as you can see.
Cut the model in half one way and the other.
Now there will be times when you've misplaced to seem.
So let's try removing a scene now.
It's very similar to what we've done before by adding a seam.
It's just another option there.
So I'm going to select this edge loop running along here and the one the other side.
Now I've done that.
I can either go to the tool shelf or control an E or down to the menu if you want to go through a menu
system and clear the scene.
Now when I go into edit mode and select all and unwrap we have a different unwrap this time as you can
see there's lots of ways that you can cut things up and depending on what you're trying to apply to
your model will depend on how you decide to cut it up.
In this case it all of these are valid unwraps some are just easier to work with than others depending
on what you doing.
So this would be a brilliant unwrap if you were working on an eye but not so brilliant unwrap if you
are working on a map of the world mainly because none of these can be stretched to fit a map properly
of course you can go really silly and you can select everything and mark it as a seam I don't know quite
how this is going to turn out.
It's probably just going to turn out to have a lot of little squares so let's go unwrap Yeah.
There we go.
It's literally every one of these faces is now his own island.
Obviously that's a bit extreme but you might want to play with the various options that you've got here
so I can select a couple of segments here as we go around our.
I was going to select them at random.
Oh I want that in a ring.
There we go.
So we selected the lead segments I can mark them as a seam and we'll get some probably Cresent shaped
unwrapped when we go and unwrap it.
There we go see problems in maps of the world that look like this when they're unravelled.
In fact that's how a lot of early Globes were made when they folded all the bits of paper that they
printed the map on onto a globe to make them.
One final thing that you can do rather than hitting you and unwrap every time is after you've made a
change to let's make one final change here.
I'm going to highlight everything and clear those scenes and I'm going to send it back to that equatorial
cup that we had before which is that one there are marked for scene.
OK.
So now we've done that if we select.
All we can go over to the image editor and unfortunately it's not the U.K. it's actually v e key.
Well the unwrap again.
And that's also available under uv's on the menu option and unwrap as you can see there's very powerful
it stops you having to muck around over in these 3-d ED all the time.
Incidentally these other ones kind of ignore your your scenes so if we go smart TV projects it's pretty
much ignored.
Those scenes all together in fatties that's totally unusable for anything I can think of at the moment.
Let's go ahead and give your knowledge a little bit of a test with a challenge.
Okay so this one's going to look a bit straight forward but it's can be conceptually hard to work out
how to play scenes on a 3D object which are going to make convert to a 2D object.
So what I'd like to do now is place the appropriate scenes so that you can unwrap a cube so it looks
like this.
And we've seen this animation before so we end up with that cross shape.
That's how I want you to unwrap a cube.
So pause the video and give that a go.
Okay guys.
Welcome back.
Let's go ahead and unwrap a cube.
Okay so we're done with this sphere for the moment.
I am literally going to hop into objet mode and delete it.
I don't need to start up a new blend file and I'm going to add in a cube.
Okay so we've got the cube in front of us and then hop into edit mode.
Now I've got to visualize chopping this up so I'm going to select a couple of edges under me bring up
the tool shelf here so I can just go Yeah definitely that one.
There's going to be a top to it's office square I'm going to represent that the top of that cross.
So that is going to be there.
Mark seam and there.
So that's definitely one bet.
Then it comes out.
So that would be the middle bit of a cross.
So it needs to come this way so it's that one there.
Mark scene.
And this one here Mark scene.
Or is it all this can be confusing so that there no it's not that one there at all.
This is why it's conceptually hard in 3-d to get this in your head since Hashi there of all places.
And that creates the cross and there's no seam across here to this spear here as that seems there and
then it's this is following round and then we end up with two bits there and there.
So we just need to chop all.
I've lost my bearings now so I've got that bit there a seam here and I think it's there there and there
of course what we can do at any point of filling those in.
I'm just going to see if I've got that top bit right.
Well we've got some of it right as you can see and then it's twisted and distorted the rest so let's
put in those three seams there and Mark seen them go over here.
Select everything.
E to unwrap.
Okay so we're getting closer.
I've obviously joined the wrong two together so I'm going to try that scene.
I think that's actually the one I had the first time I've rotated this thing round so much I'm not surprised
I'm not dizzy.
So let's try to unwrap again.
Yes there we go we've got that cross shape.
So what does that look like.
That looks like.
Let's just clear the selection there.
That looks like two seas or two ends joined together either side so that's worked out pretty well as
you could see it can be quite challenging even with a cube just to get the right seams the ones that
you want.
Or in this case the ones I wanted you to get just right in order to do the unwrap.
This is a great first step to understanding how to unwrap models.
Now it's not an exciting procedure.
I've never met anybody who relishes the idea of unwrapping a model.
It's one of those things that has to be done in order to do it and it can be a bit mind boggling.
It is very satisfying however once you managed to get it right.
And of course next time we'll be looking at scenes that are on slightly more complicated shapes but
until we get to that point remember to share your work in the discussions.
And I will see you guys in the next lecture.