Welcome to Subdivision!
In this video we're going to go through what subdivision is and
also cover the dangers of subdivision. So let's hop over
into Blender! Let's pick a
very straightforward surface. Let's go for this one here.
Now, when we have a look at this, we can go,
once it's selected in Edit Mode as a face, because we're
subdividing a face at this point. We can also subdivide an edge
as well, it's simply going to cut it up equally. So
on the Tool Shelf itself we have the Subdivide button there
next to all of the other modifiers you can
use, and we can also use the W key, which will bring up
this Specials list and we can pick Subdivide.
And we can see it's split it into four equal portions,
height-wise and length-wise. Now down
in the lower-left, the modifications the operations
tool for the Subdivide, until we select away it will be there,
and we can increase the number of cuts. Now you have to be incredibly careful,
because this is exponential. If you divide..subdivide
something too many times, you'll end up with Blender crashing
on you or your computer grinding to a halt, so
I wouldn't recommend going crazy with the subdivision.
If you need more detail, in a certain area, like let's say this
lower-left hand corner, go in and subdivide
something else. So lower-left hand
corner here. Let's go in and subdivide that and
then subdivide that, rather than cutting the whole
model up into smaller pieces. Although you'll get
much better control it becomes far more fiddley to work with, the smaller
your geometry gets or the more detailed it gets.
So what would I like you to do? There's a challenge
coming up!
So I'd like you to create a doorway into the temple!
Let's go and create that now!
So the surface that I'm going to subdivide is this one
here, this face, and I'm just going to subdivide it once, see
where we get and subdivide it once more.
There we go! So now we've got equal sides, and I'm
going to select these here.
And once they're selected, we can extrude them
into our temple. I'm going to turn off snapping and just move that in.
Now at any point, we can decide to add
further geometry inside, but we do have to be careful.
That is, if we make the inside here too detailed,
it's going to look very odd compared to the outside. So if we were to,
let's say, go in here and just make the doorway...
Yep that's it! Let's push that in a little further, and then,
in here make another doorway
going off this way.
And perhaps splitting this
area here. Let's
subdivide that, switch to Edge Select,
see if I can get that vertical line there.
I have! Excellent! The 3D Gimbal is just
getting in the way there,
so I'm going to grab that and move it in the X direction,
along to there. Now hopefully that's split
up our geometry. Ah, it looks like a double
made an edge at some point, so I'm just going to undo that.
Oh, I just want to move that in, I didn't want to subdivide or anything.
So let's select that and then move that in. That's fine, that's
moving freely. So X, I'm going to just move that in there,
because then I can make another doorway
and just push that in. As I said, we do have to be careful of how much
detail we decide to put into our model, because the more you put in
the more odd it's going to look compared to everything else. But I think that's about
the right level of detail. If there we some shadows casting in there it wouldn't just be a blank,
it would look like there was something in there at least. And
there's one final thing I would like to cover. If you have made
a very similar model to mine we will notice,
at the top here, we have what we think is a
square. However if you decide to subdivide
this, my natural instinct would be to go ahead
and delete these faces
here and make a nice square, so I can split it up into equal areas.
So let's go and try and do that now and see what happens! I'm just going to Delete
the Faces. I'm going to switch to
Edge Select and select the edge loop running around
the top of this model and just press F to fill it in.
Now, if I click Subdivide, now my natural instinct
tells me that's going to just basically chop that square into quarters.
So let's hit Subdivide and nothing happens.
So let's switch to Vertex Select to see
what's going on there. And we can see that this square is
in fact not a square. If we look up here we
can see that the Vertices that I have selected are 16. In fact, this is
a 16 sided square, it just happens that some of the sides
lie in line with one another. Now this is a special
case where it's called an ngon, a numbered
sided polygon. In this case it's a polygon that looks like a square but, in fact,
has 16 sides. Now you cannot subdivide,
Blender doesn't know how you want that to be subdivided,
because it's so confusing for it, basically, even though in our
minds we can see that as a square. So in order to create
geometry on top of our model, we're going to have to create it separately
and then manipulate it on top of our model. So let's go
ahead and do that now! I want a couple pillars on top here, so I'm just going to undo the
subdivide, because I really don't want
all of those vertices on top of my
model. And in fact, I'm just going to undo it all together so I can
play with this area here. So if we go and select these
and Subdivide, it will subdivide the faces. If we select
there and Subdivide that, we end up with something that we can start working
on. So I'm going...That is a square I think. Yes it is!
So that's a square there. Can we join that into
one object? Cast
your mind back to when we were making our plane
earlier on. We could merge these
together. So if we Remove Doubles, that sounds an odd thing to say,
and turn up the Merge Distance what happens? Well,
It puts it all into one place. So let's do that for
the entire top of the model and see what happens.
Eventually I presume that this would merge to a point.
This is where the Circle Select comes in
handy. Remove Doubles.
Yes, that moves it to a point! Let's see if there's
a happy medium for us.
Ah hah! That's nice! So we
can play with this and we end up with our four squares on top. It makes the
geometry around our model a little odd, but that's
actually made it so we've got our four squares. And then,
we can subdivide them into the areas we want. Now,
there's a bit of a stroke of luck there that wouldn't always work out for you. What
I was going to propose is, now you've got that small area there, you can remove those
faces and then recreate a square in there, and it would
only have four vertices for that square. Ah but now we've got
this area here, that was very fortuitous. We can lift these
up to make our special areas here,
and it's in danger of looking a little
wonky, so scale that one in on top.
And as we can see there, it hasn't scaled into the center. In this
case I don't mind but you can see that it's a bit wonky,
whereas before you wouldn't have expected it to do that, and that's
because it has extra geometry around the edges
here. So whereas this edge here and this edge here
are just one face, these are two faces. So
it weights the extrusion or rather the scale slightly differently.
Of course, once we've done that, we could grab it and limit
it and move it so it's roughly in the right place again. And unless
you're being super, you know analyzing it down to the
core you probably won't notice, because you're going to be
over here. Alright, that sums up this lesson!
How did you guys get on to create anything fancy? Let's
see your creations in the discussions. Take care!