Welcome to the first lesson where we are going to be learning about UVs and learning how to create them
for ourselves, and I'm just going to reiterate again that UVs are incredibly important.
You cannot skip this step in any program, in any application of 3D because every model needs UVs to
describe where and space the texture is going to be.
So we're going to work in the Ghostbuster trap, no UVs scene files.
So you should have this downloaded and you can open up and follow along.
Or if you followed part one of the series of 3D modeling, you should have your own modeled as well.
So we are modeling this.
We did not take into account UVs.
We were just kind of, you know, scaling stuff up and down and moving vertices.
And we did whatever we wanted and that was fine.
We got the model done.
But now what we have to contend with is the fact that we distorted the UVs of all these things.
So let's take a look at what I mean.
Let's let's create a new square.
It's going to drag this up.
I'm going to open up the movie editing tools.
So I'm going to go to the workspace and I'm going to scroll down to movie editing.
The other thing we need to do is go to Windows settings and preferences, plug in manager and make sure
that we have turned on the unfold 3D bundle and check it loaded.
And you can also check auto load if you want it to load every time you open fire.
And so now we have those loaded.
We can use some of the tools and the movie tool kit here.
But so what we're looking at is the actual UV space here in this window.
This is two dimensions.
You along the bottom and vias along the top or vertically v four vertical.
And let me hit Albe and just change the color here so we can see the numbers a little bit better.
But you can see that it's basically in a zero to one space.
All of these moves are in zero to one.
So we have this square selected and can see this kind of represents a folded out version of it into
a flat plane.
Now, let's select a 3D object like this door, a rectangle that is a much different 3D object shape.
So we click that it looks pretty much the same.
So what does that mean?
Well, let's turn on this little checker box icon here and we can see what a texture would look like.
And we kind of preview what the moves are, how they're represented on 3D object.
And for this kind of default square, we can see that it's pretty correct.
You know, the checkerboard squares are square all along each face.
And if we select the door here, we can see they're super stretched out and they are really distorted.
So if we were to apply the same texture to both of the of these things, let's just say, you know,
we wanted to look like concrete or something.
The concrete texture would be super stretched out in the street here.
OK, so and let me just re-emphasize, this is not the most glamorous part of learning 3D.
And but again, you're just going to have to learn it because there's no way around this stuff.
And this is just the nature of 3-D.
All the models that you create will have to have UVs, even models that you buy.
Off-line may not have UVs with them and you might have to create them yourself.
So this is this is a very, very, very important skill to comprehend because there's no skipping this.
Everyone has to understand this and learn it if you're going to learn 3-D.
Let's take a look at how we resolve the issue that this rectangle has the same UVs as a square and we
want this texture to look the same as the square.
We want squares wherever we go so that we know that any texture that we apply to this object here is
not going to be distorted like this.
OK, so let's delete this and isolate select by clicking this little button up here, the one of these
door panels, and we'll kind of focus in on it.
Let's go to the face mode and select the top faces.
And I'm going to include the Bevell on this.
And we can actually turn off this texture to make it a little visually easier.
Just like these things.
I'm holding down shift and selecting and rotating around, and I just dislike that.
And the one trick to this that we can use to our advantage is the fact that these door panels are facing
in the same axis, which is the y axis.
It's up and down.
So we just want to make sure we get these corners as well.
So what I'm doing is selecting where we want to create new UVs and.
Just in general, when you're creating new UVs, it's very flexible.
You don't have to select the whole object by itself and try to make all moves.
At the same time, you can select individual faces and project new UVs just for those faces.
So let's go to the movie menu and we can scroll down to Planer and let's click click this option box
here.
So let's try this over and see what our options are, we have a projection to plane or bounding box,
bounding boxes, what we want and we want to project from the y axis, because that's up and down that
the vertical axis.
And we want to make sure that keep image width and ratio as on, because if we don't have this on,
I'll show you what happens.
I'll hit appli.
And it takes this really long rectangle and it tries to make it into a square.
It tries to maximize the surface area of the texture, which may be useful if you're painting on this
thing in my eye, which we'll do later.
And you want to make sure that, you know, if this is an image, this square image is one hundred pixels
by one hundred pixels.
You don't want it to be tiny little square in the corner because then that really means that this entire
texture would actually only be taking up like, you know, 10 pixels by 10 pixels in this entire image.
So it could be useful to try to maximize the space to make sure that the UVs are taking full advantage
of the dimensions of a texture.
You can see that it's distorting the UVs still and this is not what we want.
So if we turn on keep image with in height ratio, that will respect the shape of the 3-D object.
So when we hit appli, it's going to make sure that we get the squares that we expect.
And because we chose these beveled edges, these these squares bleed over that edge.
You can see where it stops here because we didn't include this.
These are facing another in another axis.
So we need to select those and do those separately.
The one little catch here is the fact that we did the top and bottom faces together.
So if we look over here in the movie menu and we turn on this little blue button here, this little
middle button excuse me, that we can see that we have blue down here and this is kind of like a purple.
So that tells us something is up.
So if we're right, click and hover, we can choose UV or UV shell.
Let's choose UV shell.
That means the whole thing.
And let's click the top one.
And you can see up here that we're clicking which one we're clicking.
Let's take a look.
We're clicking the top one here, so let's click that and now we hit w we can translate that up.
So now we can see that we have blue here instead of it being purple earlier.
You know, this part, as we can see, these are overlapping.
So these colors just denote to us that these moves are overlapping.
And if we wanted each face to have a unique texture, we wouldn't want this to overlap.
Right.
So we need to make sure they're there in their own space.
And that's actually called laying out UVs.
And there's tools to help us do that.
So let's select everything we can go down to arrange and layout and just click layout.
So now I'll lay everything out accordingly and not have them overlap.
The only problem we have now is this thing is red.
What does that mean?
That means that these UVs, this face, because we projected them together, was actually projected,
you know, through this 3D object to the back side of those faces down here.
So these are flipped and that's what red means.
And we can get that with this little tool.
We can turn this on and off.
So now we know this is ready to flip this around so we can do that with the transform tools over here
and we can scroll down.
And instead of rotating, we want to rotate it.
We want to flip it.
So let's flip this thing over.
And now it's blue.
So now we can see everything's blue.
They're all facing the right direction.
But we still need to resolve these edge pieces.
So let's select them.
And I'm still in movie mode.
So let me right click and I can go to a movie.
And if I hover over it, it'll give me the two options.
I'm going to go movie or TV show right now if I have her back, we just want to give faces because we
want to select these things individually.
So I'm going to include the bevels on this axis and.
We're going to shift select all the faces that are kind of facing the same direction and let's see what
direction that is, I go up and I can see my manipulators pointing the blue means the Z axis, and also
look down here in the bottom left.
This means the Z axis.
So when we open back up this planer projection tool, go down here, click there, we can choose Z axis
and we have image with ratio height on and hit apply.
And if we go back to the text option here, the check the checker box, we can see that in fact, the
these are the correct size and dimensions of checker box for what we're after.
So we did a good job.
But again, because we did these together, it will need to flip this side over.
So if I click and go to a movie, you've shall I hand select this side and I can go down and click a
flip.
And all we need to worry about is the fact that they're right on top of each other again.
So I can select all of these again, go down to layout, click layout, and now they've sorted it appropriately.
So when I click off, I can see everything's blue and nothing is overlapping.
So we just need to finish up with grabbing these two faces and let's choose the X axis, because that's
the the way they're facing it head apply.
And now we have another issue that we can talk about.
So look at how small these checker's these checkerboards are here.
Look how big these are.
So they're not the same Texel density.
OK, so if we apply the same texture to both of these, one would look bigger on one face and smaller
on other.
And we want to have the same Texel density across the movie.
And you can see there's it says it right here, Texel density.
That means pixels per unit.
So we need to address that.
The first let's deal with the fact that these are overlapping and one of them needs to be flipped.
So if I select off of this, it looks like this one's red.
Let's actually just move it up and see if that's, in fact, the one that's red.
It is.
Go down here, flip it.
And now it's blue.
Let's select everything and click layout again.
And now it's all nicely organized.
So let's select let's say we want this type of Texel density.
So let's click this and we'll choose get and you can say, see that these numbers change over here and
we can also choose a map size for it.
But we're just going to focus on this for now.
So we've gotten the Texel density of this.
So if we choose this and set it, it's going to change to that exact same Texel density so that we know
textures are going to be look the same scale wise so we can click this one and it's set as well.
So let's just double check that.
These are also set to that Texel density.
They were pretty close, but not exact.
So it's one way to just get everything to be totally exact and same across the same object.
So that's pretty cool.
So in the next lesson, I'm going to discuss how to merge UVs back together because now they're on in
different pieces.
And let's say we want to wrap a texture around this edge.
We can see that the checkerboards are no longer lining up.
So let's resolve that in the next lesson and learn another form of projection.
Thanks for watching.