Welcome to Edge Loops and Loop Cut and
Slide! So in this video, we're going to go through what
edge loops are, how to select an edge loop,
then we're going to move on to the power of a loop
cut and show you how to control it's slide function,
the loop cut and slide. So let's hop over into Blender!
OK, so we've got our
pyramid here. Now I want to demonstrate an edge loop
for you. So if we've selected an edge... Let's just
pick an edge down here. Oh, we need to be in Edge Select and Edit Mode,
if you're not already. Ah, we've selected this edge here. And
now an edge loop is just a continuous series of edges. So there's an edge here,
an edge here, and then it disappears behind the model and it comes back again. So if we go to
Mesh and go to Edges and then
somewhere down here there's Edge Loops,
and you can see it's selected that loop of edges.
Now the shortcut, the keyboard shortcut for that
is Alt. So if you're holding down
Alt, when you click an edge
like so, you will select the Edge Loop.
Now, in this case, all of these go around in a loop.
However, if we were to select this edge here, whilst holding it down, you
can see it terminates at the top and, in fact, terminates at the bottom.
And the reason for that is because these other two edges
have come in and created what's known as a pole,
where three or more edges join together. There is another exception, where
you've got a quad, where if there was fourth line coming in, it would probably
continue this edge loop all the way around our model. And
the same happens with these top edges, if you try holding down Alt and
clicking, you will find that they also don't go anywhere.
So that is an edge loop and we can use that to
select our edge loop, when we need to modify it. So let's
try using a loop cut!
Now the great thing about this is that
you can literally cut up your geometry and create more.
So if we hop over into face mode, you can see that there are
only four faces around the top of this pyramid, and
if we hold down the shortcut keys Control and
R, at the same time, we end up with this pink thing
appearing on the screen. This is how our model is going to be cut up.
Now the way that it's deciding where to
cut, as you can see if I go towards this top edge here
on the pyramid it cuts around our model
and the same over here. If we come towards this edge, it cuts
around our model, and that would happen on all of them.
By default, this is a proportional cut.
By that I mean 0 is in the middle, so let's
left-click once, and we can see towards the lower-
left it says Edge Slide. So this is the slide part of
our cut, it goes from 1 all the way across to
-1. So it's a proportional cut and 0 being bang in
the middle. So because I've moved it, which you're going to do all the time,
I'm just going to press 0 before I
finalize that cut. Now if we hop back over into
face mode, we can see it's divided those faces.
Alright, so I've just opened up a brand new Blender file, just to show you something
with a loop cut and slide, that I don't want to show you on the pyramid, because it's a bit too
complicated or complex, sorry, to show you on
that geometry. However, a nice simple cube, it's brilliant on.
So I'm going to hop into Edit Mode really quick, make sure Edge Select
is on, and I'm just going to make this shape here
a bit more like the pyramid that we've been working on, and I only really care about
this front face. So when you're doing a loop cut and slide, when
the faces aren't already parallel at the top of this
square, let's go and put a loop cut in now.
So Control and R and then left-click, and then it enables
this slide. And as I mentioned before, it is a proportional
slide, and you can see it goes more and more
at an angle, as it goes towards the left or the right. Now
in the middle,um, it's 0, and on
the left it's -1 and on the right it's 1, and we can
see that edge slide in the lower left-hand side.
It's going all the way, as I say, down to -1 and up to 1.
In this case, I want to put it bang in the middle, so I'm going to hit the 0 key
and just press Enter, and that fixes it in that location. Now one
of the great things, when you're cutting up any mode with the Loop
Cut is, you can actually place geometry on top of one another.
So if I go and create another loop cut now, with Control
and R, and we can just see it there. If I move it
across and bang it straight up against the previous
cut and then select, well actually apply
that change, there's extra geometry on top of
one another, at the moment. Now I can use the 3D Manupulator
now, just to pull that out, and we can see, if I switch on
face mode that there are three separate faces. So it's great being able
to put geometry on top of itself, without
worrying about it too much. Now remember, if you've done this the model can
become very messy, so make sure you do it with intent and
do something with it immediately, rather than just leaving it, otherwise it's going to
cause you confusion later on. One final thing to mention,
if you're doing this type of thing and you've got Proportional
Editing turned on. So the shortcut for that is O, so you
might have hit O by accident or indeed enabled it
down here. Now, one of the things you will notice when Proportional Editing
is turned on, is if I do the same thing again
and put one on top of the other and then try and
move it, ah there's not an extra bit of
there's no extra geometry created. And you also get this circle on the screen,
so that's a good clue that you're in Proportional Editing mode, when you start moving
things. We'll go through that actual tool later on,
but just to make you aware at the moment, it's almost the same as if you've had
merging your vertices turned on, when doing that
thing there. So make sure you've not go Proportional Editing turned
on, if you're doing this type of action, and you're going to need that
in the challenge coming up!
It's challenge time! I'd like you to create
a ramp for our steps, using the Loop Cut and Slide
feature. It just needs to be on one side of the pyramid for this
exercise, and we're going to be creating the ramp needed
for some stairs.
And to give you an idea of the end result I'm going for, it's
a parallel set of steps like this. It just makes creating the
steps going up easier later on.
Pause the video now and give that a go!
Welcome back! How did you guys get on? Now, before we hop over
into Blender, what I need to make sure is that you're not skipping ahead. I
really must impress the importance of trying out these challenges yourself,
and if you're not able to do it, put the owe-ness back on me,
your instructor, your tutor. If you're having difficulties,
if something wasn't clear enough for you to be able do this challenge, then I
need to modify these videos to make sure it is very clear for you.
So without further ado, let's hop straight on over
into Blender!
So we've already made one loop cut down the middle
of our model and divided it in two.
We need to make another one, so I'm just going to go
Control and R and line it up there.
And I'm just going to move the mouse, at this point, and I'm going to ram it up against this one
and put those two edges literally on top of one another.
Now once I've done that, I can now control
where those edges are in our model.
So I'm going to hold.. I'm going to press G and I'm just going to move it. If you moved
it the wrong way, the model will go a funny color. And now
I've moved this out, and I only want it moving in...
I'm looking down here, towards the bottom-left, the y axis, I'm going to press y
and that's locked it into this axis. Now,
I want to move it, by the looks of it, by about 1 and 1/2.
I'm going to type in 1.5 and press
Enter. Now I can do the same thing with this
edge loop, but I'm going to have to select the edge loop first. I'm going to hold down Alt
and select it. Then, I'm going to grab it,
moving it only in the Y axis, by
1.5? No, - 1.5!
So -1.5,
there we go! So that's created some fixed points at the top
and the bottom, that we can link up. And the final thing is to
create our ramp, so I'm going to
I'm going to select these bottom two vertices.
I'm going to hold down Shift to select multiple vertices. I'm going
to, still holding down Shift, I'm going to press these two vertices here,
and then, I'm going to press the F key to
generate a face. Now that face is inside our model.
I'm going to now change the view to Wireframe,
and that also has a shortcut key, which is Z.
By pressing Z, when you've not got anything selected, moving, rotating,
etc. it will in fact switch to Wireframe Mode. And we can see
underneath, that ramp is ready for use.
How did you guys get on?
I will see you guys in the next lecture, where we're going to use that ramp
as the base for our steps.