OK. So it's been a while since I've made a video,
and to the disappointment of a few people this one's not going to be about making the Knight for
the chess set. I want to go over another heavily misunderstood and mostly unused tool. And that
tool is the curve tool, which lives within loop tools. Now, the process we're going to use is
generally called "cubic interpolation" but it's more commonly referred to as "panel beating". As
in the type of work a car mechanic might do to work out the surfaces of a damaged metal panel
from a car. So let's get started. So if I just delete the Default Cube I'm going to press "Shift"
and "A" to add a "mesh plane". I'm going to move the camera forward. "Tab" into edit mode and
subdivide that, let's say four times. Two. Three. Four. Good. So we've got this grid and what
you'll see people doing is - along one of the edges they'll select a vertex, or more than one. I'll
just use one point here. And they'll move it. So I'll press "G" and I'm going to press "Y" so that it
just moves along the Y-axis, and I'm going to move it out a little bit. It doesn't matter where. Now
I can select this corner point. "Shift" and select the point I moved, and then "shift" and select
another one at the other end of this Loop. It doesn't matter which order you select the points
in. If I now press "N" to bring up the N-panel, and go to the edit tab where my loop tools live.
I can press "curve" and we can see that this edge is transformed into a curve between our three
selected points. I'm sure you've seen that before; that's how everyone seems to use the curve tool in
loop tools. And they never go beyond that. And I guess that's useful but that's not really what we
use the curve tool to do. It's much more powerful than that. Let me just undo a few steps and I'll
talk about how it works on this simple flat grid. Actually, first of all let's look at how I often
see people trying to curve a surface like this, and we can see some of the problems. If I click
this little circle up here at the top of the 3D view we can turn on proportional editing. And then
I'll go to the grid and grab a point somewhere in the middle. And I can just press "G" and "Z"
to move it up and down, and you can see this curvature being created across the surface. And
this tool is using the circle you can see around it to decide how many points it encompasses on
the mesh to create this curvature. It's a great tool and you'll see me using it all the time in
other videos. But it has some problems. Firstly, the shape of the area that we're moving is decided
by this circle. And it's always a circle. That can't be changed and that's quite a big problem.
When I scroll my mouse up and down to change the size of the circle, I can make it quite large
you can see that the edges of our mesh are being pulled up. And we very rarely want this to happen
or if we do we want much more control than this. Proportional editing is powerful, but it's very
limited. There's a much better way to curve a surface. So let's just undo this and start
to change the curvature using the curve tool. So first of all I'm going to turn off proportional
editing. We won't be using that. And again I'm going to select a point in the middle and move
it up in Z so I'll just press "G" and "Z" and move the mouse. And this time it's the only
point that moves. And what we're describing here is the peak or the apex of the curvature
we want to achieve. So, I've moved this point out but we want the whole surface to match this
peak. And I do that by selecting the two points at the very edge of the same Loop that our moved
point is on. In either direction. I'm going to do it from left to right but you could go from top
to bottom too. So, I have a point to the left, The point we've moved. And a point to the
right. All on the same Loop. And I can now go over to the N-panel and press the "curve" button. And
it's just the same effect that we saw the edge, but now we're doing it in the middle of the mesh.
And it creates this Ridge which has been created by moving the unselected vertices into positions
between the ones we do have selected. And that's the important thing to understand at this point.
The curve tool works only on unselected vertices. So, we've made this Ridge, it's not really what we
wanted, but the next thing you need to understand is that the curve tool is designed to work between
Loops, Not just between vertices. That's why it's in Loop tools. So now I can "alt" and "click" on
this loop at the bottom to select the whole thing. "shift-alt" and "click" on the loop at the top and
finally "shift-alt" and "click" our curved Loop in the middle. And now when I press the curve button
in the N-Panel, we'll see that the whole surface has now been curved; to match the single point
that we originally moved. But very importantly, all the vertices around the edge are in exactly
the same place they were when they're started. Unlike the mesh we ended up with when we used the
proportional editing tool. Which pulled up those edges and all the vertices with it. We've decided
on the limits of the curvature ourself and this is a really important distinction. So this is
getting a little more useful and we do use this functionality. A lot. But it's still not really
what you'll use the curve tool for. most of the time. the main use, when you're starting out using
it anyway, is to fix problems on a surface. And we can use this newly curved grid to talk about that.
Let's say we had some points selected on this mesh and we were moving them around to shape it. it
doesn't really matter which ones or how many or where we move them to. I'll just select these
two here and I'll move them up in Z, to make these bumps and maybe I'll scale them out in Y and we've
created this feature, on our fairly complicated curved surface. And that's great. But what if I
now moved some points somewhere else on the mesh. I'll just select a few over here, and I'll move
them up in Z and maybe back in X. I'll scale them in Y. Whatever, whatever you're doing to make your
shape. And all of a sudden, while we're working, we decide that we really like this area here. But
we don't like these two bumps anymore. What can we do to get rid of them? Well it's really difficult
to move them back into place or to smooth them out or average them or rebuild them; without the
surface becoming very flat or too curved. You will always end up with bumps and errors around
this area. We can't use undo because we like this part of the back and pressing undo would get
rid of that. We may have done hundreds of other modeling changes since we decided, we just don't
like these, and we don't want to have to undo all that work. But we need to get rid of them, and the
curve tool is used to do just that. What we do is, we select the points we don't like, then we press
"Ctrl" and "I" to invert the selection. So that the rest of the mesh is selected, and our problem
points are unselected. And remember that I said the curve tool only works on unselected vertices.
So if we press the "curve" tool at this point, then blender will rebuild the curvature using
these unselected points. But with respect to all of the curvature surrounding it and that's all
calculated cubicly, which effectively makes the continuity perfect. And that is really impossible
to do any other way. And maybe I didn't want to get rid of those features completely. Just reduce
their size. Well, again, that's possible with the influence slider in the properties box down here.
As we move this, we can see we can actually reduce the magnitude of a feature. Always with absolute
respect for the curvature around it so things can easily be reduced in size. Or eliminated
altogether. And we can continue shaping this surface and making changes and we will always
have the ability to reduce or remove features as we want. Just selecting a few points we
don't like and pressing "Ctrl" - "I" to invert the selection and use the curve button. There
are all sorts of reasons vertices can be moved out of place on a mesh, and with the Curve tool
it's very easy to rebuild complex curvature. It actually works very well as just a flattening tool
itself. If I select the two Loops at either side of this mesh and press the curve button, the
whole thing is flattened down. Or if I want, just reduced in magnitude, by using the influence
slider. And this method is great for altering and fixing curvature on spheres, cylinders, toruses.
Any kind of curving shape really. So, well, let's show you. Let's just start a new scene. I'm
going to delete the default Cube and press "Shift" and "A" to add a mesh torus. I'm going to set it
to "shade smooth" and press "Ctrl" and "2" to add a subdivision surface modifier to it. In fact
let's make it even more difficult to work with. I'm going to go over to the modifier panel here
and add a "simple deform" modifier. I'll leave it as bending but I might increase the bending
value. And if I apply this modifier and then "tab" into edit mode, you can see we have a really
complicated curved base mesh. This is the kind of curvature which can make modelers really nervous
about making changes as it seems very difficult to reverse or reduce your changes. But we really
don't need to worry. A mistake often made when working with the mesh is that vertices get
moved by accident. I might have, at some point, selected - let's say, I don't know, three vertices
here. And they get moved somewhere by accident. And the camera's facing the wrong way to see them,
and you might keep working away. It happens to everyone. Happens to me all the time. I should
probably be more careful but it's not as big a problem as you might think. But anyway you keep
working away. Maybe I've selected a loop around the top and and, well, let's make something
quickly. I might use a "checker deselect", and I'm gonna have seven deselected vertices for
every one that is selected around this Loop. Oh, and you always need to enter "-1" for the offset
in Checker deselect. I talk about that in another video, so I won't go over it again here. But you
do. So always change that to minus one. And let's say I expand these points out to create these
little Islands at the top just by pressing "Ctrl" and "plus" uh maybe I'll move these up a little
and then I'll press Ctrl minus and just move the original inner point open maybe scale that out.
Whatever you're doing to create your models. And then I've got my shape and I spin the camera
around to look at my handiwork and suddenly I see these vertices here. It's not part of my design,
it's just a mistake and now our mesh is really very complicated. To put these vertices back
into place is virtually impossible. You can try to delete them and rebuild the geometry with new
faces or smooth them out somehow. But it's never going to work properly. There are always going to
be problems in that area. Unless we use the curve tool. So again, I just select the vertices
that are incorrectly positioned. I'm going to press "Ctrl" and "I" to invert the selection,
leaving everything other than these three problem vertices selected. Now I press the curve tool and
our problem's gone. It's as simple as that. All the curvature has been rebuilt correctly. Light
will flow over this surface perfectly because all the calculations are cubic and that's why
we call it "cubic interpolation". Mostly, we do call it panel beating, but it is actually
cubic interpolation. And again I could just use it to reduce the size of some features on my
mesh. Maybe I wanted these two pointed shapes here to be smaller than the others. I'm going to
press "Ctrl" and "plus" to encompass all of the moved points within the selection, then I press
"Ctrl" and "I" to invert the selection. Hit curve, and of course they're gone. But I can just use
the influence slider until they are the size I want them to be. Maybe that's all I wanted
to do, just bring them back to this smaller magnitude. Or I might have done all this work and
decided I don't like any of it. But I do like the underlying curved Torus base mesh. So again I
go around selecting all the top points. Press "Ctrl" and "plus" and then "Ctrl" and "I" to
invert the selection. I'm going to hit curve and make sure the influence sliders at 100
percent, and all that detail is gone. With this really very complicated curvature around
this warped torus rebuilt perfectly. Light will flow over this very smoothly. So that's
one very powerful use of the curve tool. Now, another use of the curve tool is when making
vehicles, spaceships, the hulls of boats, guns, all sorts of sci-fi objects. It's used extensively
in character modeling. In this context, it becomes a modeling tool rather than a repair tool. And
you'll find it to be excellent at creating complex curvature on top of other complex curvature. So
let's start a new scene. I'm going to quickly try to show you how panel beating is used to do this
kind of thing. I'm going to delete the default Cube. I'm going to press "Shift" and "A" to add a
new mesh plane. I'm going to "right click" to set it to "shade smooth" and I'm going to press "Ctrl"
and "3" to add a subdivision surface modifier to it. I'll tab into Edit mode and I'm going to scale
this panel by pressing "S" and I'll type "2" and press "Y". Just to scale it along the y-axis. Now
we'll need some geometry to work with so I'm going to press "Ctrl" and "R" to add Loop Cuts I'm going
to hover over this top edge here and type 20 and hit enter to give it more divisions. I'll press
"Ctrl" and "R" again and this time I'm going to hover over an edge at the side. I'll type "10"
and hit "enter" and we end up with what seems like a good enough geometry for a couple of door
panels. So I'll go with that. And you'd often be working with a reference or a blueprint. I don't
I don't have one I'm just, I'm just going to try to quickly show you the general principle of how
it works. Anyway, you'd be matching these things with a blueprint and to do that we might select
a point somewhere in the middle here and I'll just press "G" to start moving it and I'm going to
press "Shift" and "Z" so that it moves on the same plane and I'll just move this up here. I might
move this point on the corner in the same way to match our imaginary blueprint and I'll move this
one at the other corner too. And then I'll start using our curve tool again. I'll select the left
corner point, then the center point that we moved, and then the right side corner point. Make sure
the "Edit" tab of the "N-Panel" is displayed and press curve and that'll create the curve which
you just have to assume would match our blueprint or reference image. Then I might do the same
along this edge. I'll just move a point out, near the middle a little. I'll move the one
at the bottom corner. Just for the sake of it. Select these three points and press "curve" again
to make this curved edge. Maybe I'll just move the other corner the other side and just select three
points which will describe my curve at the bottom. I'll add a final curve at the side here just so
everything flows. Select these three points and press "curve". And that's great. Maybe that
would be the shape of the car panels from the blueprint or the reference we're working on.
But you'll notice that the grid in the middle doesn't match the flow of the overall shape
and again we use the curve tool to solve this. I'll "alt" and "click" on the bottom row to select
this Loop. I'll "Shift", "Alt" and "click" one in the middle. And I'll "Shift", "Alt" and "click"
a third time to select the loop at the top. Now, when I press curve, it spreads the geometry
correctly between these loops. I have to do it from left to right as well. So I'll "Alt"
and "click" this loop at the side. "Shift", "Alt" and "click" this one around the middle and
"Shift", "Alt" and "click" one on the right. I'll press the "curve" tool and you can see now that
the internal grid matches the shape very well but if I move the camera around this panel it
looks very flat and we wouldn't want that. Nothing is really flat in real life and certainly not car
panels. So maybe I'd select a point in the middle and move it up. I'll press "G" and "Z" just to
move it up a little and as I showed you at the start of the video we can use this peak to curve
the whole Surface. By selecting a point at the edge, the point we moved, and a point of the other
Edge. And just press "curve" to create this ridge. Now, I'll select the whole loop at the
bottom, the whole loop at the top and the whole loop with the with the ridge. It doesn't
matter which order you select the loops in. And I'll press "curve" again and now the whole
surface is curved, as a car panel might be; with good topological flow over the surface and perfect
continuity for reflections and transparency. I might want to move the corner points down so
I'll select the four of them. And I'll just move them down in Z. And that means re-curving the
surface and I'll do it by re-curving the edges first. I'll select these three points and press
"curve" and then I'll go to the other side. I might even want to move a point up here and
curve between these three. We can have some really complex curvature. Now I want the whole
surface to match up so I'll select the first Edge loop at this side and then one in the middle
around the apex of the surface and then the new curve point on the right. press "curve", and we've
got some great curvature. You can keep on moving points and re-curving to get these shapes you need
but I think this will do for the main surface. Now, I said that you would often want curvature on
top of your curvature so let's do that. So I take a point of the edge here and move it up and then
maybe one further along this loop and move that up. I can select both of these moved vertices
and then I might want this detail to disappear into the original curved surface. So I select a
few points at the edge. This will make the new curvature curve perfectly back into the panel
surface because all the calculations are cubic. So I press the curve button and there it is. Maybe
this is too high. And if I felt that was the case, I can select this entire loop. Press "Ctrl" and
"plus" a few times to select the surrounding loops and then I "Ctrl", "Alt" and "click"
the ridge loop. Here. And I press "curve". When you do it like this, just selecting a
few loops, you need to "check" the boundary box to make sure everything else around
the mesh doesn't move. Because it can. So, that makes it disappear as it did when we were
fixing surfaces with the Curve tool. But I can bring it back with the influence slider. Make it
the height I want and the relationship between all of the curves that's being calculated
cubically so the continuity is always perfect. OK, that looks fine. Now I might want a much
sharper detail and again if you look at modern cars you'll see this everywhere on almost every
car. I'll select a loop here and press "Ctrl" and "B" to bevel it. I'm going to roll my mouse so
that there are three loops. I'm going to move it to around here. And I'll do the same kind of thing
again. I'm going to select two points in this middle loop here and just move them up a little.
then again I'm going to select a few down at the other end to taper the curve off into our curved
panel. Remember, that the selected points won't move at all. And press "curve". And now you can
see this sharper detail running across the panel and once you start playing with the Curve tool
you can see that there are lots of interesting shapes that can be made to match kind of modern
manufacturing processes. OK, so once my main surface is done I would normally take a copy of
this mesh to use as a shrink wrapping target when I cut holes and things and add other details. But
I won't do that here, this is just a really quick demo of panel beating. But yeah, maybe I would
want to add some windows now so I'm just going to select a face here, then "Ctrl", "shift" and
select one down here to create this rectangular selection. I'm going to have "shift" and "click"
a face here and then "Ctrl", "Shift" and "click" another one here and I've got two kind of vague
window shapes. If I now press "I" to inset that, I would normally turn on edge rail for this kind
of inset, which keeps everything running along the existing flow of my mesh. I can delete or even
separate these polygons out to use as glass for my windows with exactly the right curvature. So
I'll press "P" this time actually to keep those as they'll probably be useful later and choose
"by selection" and then you can see them here as a new object in the outliner so (I've just) so
I would rename those to "Windows". It's always a good idea to rename your objects as you go.
And I'll just hide them. I won't use them here, that's just to show you how easy it is to
make useful elements. So if I select our big panel again and go into edit mode I can shape
the windows now with this loop. I'll just do something simple to one of the windows so you can
see how easy it is. I'll select the whole loop, deselect a few points on it and use the curve tool
again. I may need to check or uncheck boundaries. You'll get used to doing that and you can see
we have this curving at the back, and I can shape the windows very easily with the Curve tool.
This is where I would normally use a shrink wrap modifier with the original base mesh. But I've
not done that here for a Simplicity and speed. Now I did want this to be two doors, so I'm going
to select a loop where I want to split them up and bevel that by pressing "Ctrl" and "B" and
just make it - I don't know - about this wide. Now, if I select the very centre loop, I want to
select everything on just one side. There are lots of ways to do that, but a quick and simple
method is just to go to "select" - "select loops" and "select loop inner region". And that
just selects all of the vertices on one side. Now, if I press "P" to separate it into a new
object and choose "selection", we have these two door panels. I won't rename them this time.
But if I have them both selected and go into edit mode I can press "A" to select everything, and
then "E" to extrude. And I'm going to extrude a little further than I normally would just so
you can see what's happening. And what we end up with is this very complex curved pair of panels,
with perfect continuity between them. With curved detail on top of the curvature which runs, again,
perfectly between them and they're two completely separate objects so the door can open or fly
off - whatever you need. And when they do close they fit together like a jigsaw. And I would
now start adding other furniture like mirrors and door handles and keyholes and all sorts of
other modeling techniques are used for that and but that's for further videos. What I hope I've
shown you here is that the curve tool is one of the most powerful tools in blender when working
on quad based meshes, which need to curve as they do in real life. So let me see what else I have
in here. These sunglasses. They would have been virtually impossible to make without the use of
the curve tool. There's really quite a lot going on there but the curve tool makes this kind of
modeling much simpler and this is very similar to the way NURBS work because they're also calculated
cubicly. But in subdivision surface modeling we have more options so it's better for our needs, in
blender, to use the curve tool. This, er, this toy train steam engine. It was relatively simple to
make because I could play with the surface a lot with the curve tool, to experiment with details
and change all the curvature to match perfectly around all the little features that I add and
remove. And it's tools like these that are one of the multitude of reasons to maintain good quad
topology on your objects while you're modeling. They won't work at all on meshes that have used
the Boolean operators. It won't work with n-gons or triangles or extraordinary poles. You lose
access to the more powerful modeling tools in blender once you start using a Boolean. I can spot
up sci-fi model made with what people are calling hard surface Boolean techniques a mile off and so
will you when you start playing with these kind of real modeling tools. Let me just load up a version
of this train with just two simple modifiers on it and you can see that distortion and animation
work incredibly well. I can just increase the height in this wave modifier over here and
the topology handles the Distortion with ease. And these modifiers may not just be for
animation I might be using them as modeling tools. Because I can. Because it's all been
made with quads and certainly no booleans. Under this I've got a simple deform and I can
just play with the angle while it's playing back and there are many times when a model will
need to be changed or updated in its life cycle. We're always looking to create something called
the "framework mesh" for any given model. oh, it's our Knight - which which I haven't shown
you how to make yet; sorry about that! I haven't really talked about the framework mesh yet. But on
the left here we have what might be the "framework mesh" for this model and it would always be all
in quads. You need to understand that there'll be lots of versions of a model and some will be
triangulated and some versions will have n-gons. Depending on the destination the usage and the
rendering technologies used to display them. But all of these different versions will be derived
from the "framework mesh". That's the main model and it'll always be quads and it'll always be
as easy to edit and change as possible and that means good quad topology. When you hear people
arguing that everything is triangulated at render time anyway so it doesn't matter; well, they are
correct of course but that's not the point at all the point is that if a production or a game is
remastered or rebooted or redesigned in any way, then the original models need to be adaptable.
If it costs a lot of money and time to change a model, then the people who pay the bills
will not be happy. And framework meshes are often quads just for that reason alone. So that's
the goal of modeling, to make this framework mesh for any given model. Maybe Unity or Unreal or
Godot or VFX or 3D printing. They'll all have different requirements and triangulations and
even n-gons, and you'll often need to make all of these versions and they'll all come from
this one framework mesh - using triangulation and decimation techniques. Anyway that's probably
enough of that. I was really just talking about panel beating in this video. And hopefully
I've given you a good starting understanding of it. I did miss out a few unrelated modeling
steps that would normally be done but the video would just been too long if I'd covered all the
unrelated stuff so I think that's enough for now. Now, I'm not really completely well at the
moment so making these videos is a bit of a mountain to climb, but I will get a video made
for the Knight, for the chess set. There may be one or two more in between, but I will get
there, I promise. And by the time we're done you should have some really good professional
modeling techniques under your belt, which will make you a much better all-around modeler. OK,
well thanks for watching. See you next time.
