Hello everyone one of my YouTube
subscriber asked how to model a knot in Rhino 3D. I would like to show you the
process in this video and even more let's make it into a ring. And welcome
back to PJ Chen Design channel. This channel is to share Rhino 3D knowledge to
help students and 3D model professionals to learn various Rhino techniques.Are
you ready? Let's get started. Like most of my tutorial, I always like
to look at an image, and kind of understand the structure, before I
actually model. So go to the Google type "knot", and in the "knot" (images) you have different
kind of knots here. but I see a lot of repetition, for example, under this
one. and also those two right there. so I'm going to use this as example to
build our tutorial. so go ahead and save the image. I already saved it, and we're
gonna bring it into the Rhino, and use it as a reference. To start with it, I always
like to starting with the curve so that's bringing the image to look at how
our curve is going to position. Let's go ahead to the command bar right here, and
type it "picture frame" and then you will bring in the image you just
downloaded from the internet and then we're going to bring the image
right here. First let's use the "arc" tool to creating the arc for those two on the
outside, and then make sure the "grid snap" is on. so I'm kind of simply making
roughly about this, and kind of mirror to the other side, to make sure it's
symmetrical. Okay and look like I have a curve is gonna go from this point to
this point so I'm going to use the blend tool you're gonna blend from this point to
this point. Alright so you kind of give me a really nice curve right there.
I'm going to use a blend tool again, to blend from this to this. But
let's take a look closer on the detail. It looks like it's not blending all the
way to the bottom. it is blending to two ends. so instead of making it into the bottom
and I'm gonna draw two straight lines here. it doesn't matter how long is it
it's just for our reference, and we're gonna blend with the "blend tool". We're
gonna blend from this point to this point. okay so that's the first one. The second
one got blend from the bottom to this point. Okay so now looking at it we got a
really similar structure right there. Okay so after that let's join all of
them. Okay now they become a single curve right there, and we need to kind of
guessing who is going up, who is going down. So I'm gonna open all four views, and
still looking at this picture so now let's look at the perspective view. if I
turn on a control point. I kind of notice the one on the bottom of that part need
to go a little bit lower. Now look at this it has a kink there. It's because
when we join all together, it has all the seam where the join points (were) so let's go
back one step. If you have something like this. The first things you wanted to do
is to "rebuild", when we rebuild a curve it's going to turning into a single
curve so there will be no seam in between. Let's try to take a look the
different point. If I'm going to use the.... Let's enlarge this view. If I'm going to
use 12 points, you see how much deviation that is, right? So I need to increase a
little bit, and try to get it as close as possible. So this one is not too
bad. right so it has a little bit deviation.
and if you want to get closer you want to bump up the number a little bit more.
Okay so get it really close, and because it's real like a rope, it doesn't have to
be so geometric so that it could be accepted. so I'm gonna click OK right there
okay Now go back to what we were doing right
here Okay so now looking at this knot right at
this point. We want this knot (point) go lower and on the opposite side, this one need to go
a little bit higher, just a little bit right and you may want to turn off your
"Grid Snap" so that way you can freely to snapping into any of the position that
you want. So we want this a little bit higher. Okay so now this is going
lower. so what that mean is this two point will need to go a little bit lower.
so that's open the perspective, it is bigger and easier to for you to see. And let's move
this one there. Alright so with this and then that's moving here at this
point right here. It needs to be a little bit taller, so once you move it here I'm
gonna move this point up a little bit. and I'm moving everything with the Gumball
Coming back here. it's getting lower so I on the top view they still
look the same. I'm just moving with the Gumball. Okay and then come back here at this point, get higher so this is going higher
a little bit, and wanting to be smooth out the neighborhood points, you need to
move a little bit too. so and then it's coming back. Alright so it looks like we
have something good to start with, and let me move this down a little bit.
And we can keep adjusting until we get it close, but I will suggest you do
this way. You want to record the history and using the pipe tool, and to select
your rail, and giving the any of preferred thickness that you like Alright so once we have this and because
we are recording history and let me turn the curve into the red color, so it's
easier for you to see. now we have this we can change it with the history
recorded. So look at at this point right here. It seems it's a
little bit higher so I gonna turn on the control point right here and find out
the point right there to make it a little bit higher, so the curve will go
with it right so I need it a little bit higher
something like this, and then maybe the gap is kind of too big, right there, so
I'm going to look at the picture on my top view and kind of adjust the gap
there. I'm gonna select everything on the bottom and it's kind of moving up a
little bit, and you can see your pipe is moving as well, and you don't want to
move too much at once because it will lose that very nice flow over there. Just
move a little bit one at a time. Let's keep tweaking. I'm going to fast
forward the video, so you don't feel like don't feel boring for seeing me doing
all of this. but I want to fast forward video so you can get my entire process You don't have to worry about they are
not symmetrical because is a knot, right? so supposedly they shouldn't be completely
symmetrical to make it more human made or like a human carve from the ring.
what I try to do is to try to make sure it is matching to the picture as
possible and also delete the two ends so it's not coming out that much. As soon as
you delete it, it will be shorter but still keep the caps on the side (at the end) okay so we no longer need this image, I'm
going to delete it and before we making into the ring. This is a really important
concept I wanted to talk about here. As you can see this is a piping work coming
from one single line, right? there's a lot of intersection there right? so it's on
top of each others, and there's no way you can trim in between, right? if you try to
trim you need to select two parts, and we only have one part now beside the caps, so
it's hard to trim and why this is gonna be the problem is because, when you try
to go.... let's say we're gonna have this one next to the other one....
and I try to boolean this one in this one, then your computer will tell you the
boolean unit is failed, and the reason it's failing is because there's
a lot of a parts intersect to itself and that will cause you a
boolean unit fail. To address this issue we can do one of my trick to address
this issue here. I'm going to hide this curve. By looking at this one, I'm
gonna draw two of the curve about one-third of the model right here, so
somewhere there. The reason I put it there is I'm going to split them. So
you don't want to split in somewhere has a confusing part like that little
triangle right there. so I want to put it on the topview look like this. Let me
turn this into the red color for you. so this is really important step.
otherwise you finish the ring you will have super hard time to Boolean. Almost
impossible. okay so don't *skip or avoid this step, so we are going to use the
split tool and this is the object will be split and split by those two.
okay and it will say we break the history. that's okay, because we no longer
need to tweak it. Now you see I have a turning into multiple parts here. Okay so
my goal is making those multiple parts into the solid. so that's
starting with the right side this and this I'm going to type in command "CAP".
okay so now they are solid by looking at "property". (it shows) "close solid polysurface" so I
gonna do here, here, her,e and type it "cap" as well. Here, here, and cap it as well. so
now if you look at my perspective you're going to see they all have a surface
right in the middle for them. so all we need to do is Boolean all of
these, now if you take a look in there it's kind of cutting whatever is
touching, so we no longer have any of the shape in there. so of course
you're not able to edit at this point, so you wanna do the shape and edit before
you do this step. Okay this is really important step. so let's go to the next
step I'm gonna creating a new layer so with this new layer I'm gonna name it as
"ring shank", okay so let's go to the ring shank and let's
turn that off. Like most of my tutorial I'm going to do is 16
millimeter (diameter or) radius 8. so that's my ring shank and I don't want to do just straight ring shank. We want to do some wavy ring shank. so that me rebuild
this curve into.... let's say.... 12 okay. so I'm gonna pick up the control points at my
front view. I gonna pick up this one this one, like jumping one in between.
okay with all those pick up. I'm going to make them come
up a little bit on my top view, so you can see my perspective. Now I have a wavy
design okay on my right view I'm going to create a
profile. so let's do the arc, the straight line, I'm sorry, and then I'm
gonna use the arc snapping into the midpoint. Coming here like this. Okay and
then basically I need to join those two curves and also like to make it round it
a little bit so let's fillet the edges for maybe 0.35 (mm) so once you sweep inside
the ring shank it's not too sharp on the edge. And then I want to draw a space
that's going to cut out to make sure they line up right in the center. so I'm
going to use "align vertical tool" and maybe that's too big. Alright so this
is the area that we have I'm gonna select both of them, and trim the area
that I don't need. Okay, so onee it is done we are going to round it the
edges a little bit. Let's try 0.2 (mm) on this area. Okay,
great! so now we have a profile all we need to do is to make the surface. so I'm
going to use the "Sweep 1 Rail" so this is the rail, this is the profile, and then I
get this one here. okay, double check this is too big of the curve, my profile is
too big. I'm going to scale it down just a little bit like this. and let's do one
more time, rail, cross-section, and let's take a look on where the turning is.
Alright, I still have the folds there, if this is for rendering you probably can get
away with it but you're gonna print this is gonna be your
issue. Alright and then so I'm going to delete it. Maybe I shouldn't have done
much of the curve and let's do one more time "sweep 1" and sometimes I like to
show you that my process completely because there might be
something that you probably will experience too.
Alright so bear with me, it takes few more seconds to to understand this. Okay
so now it looks nice and I will suggest you to check on all the very detail on
each of the process and thinking about the printing, and see if you can get it
printed really well before you keep moving on. Otherwise you know once you've
done everything as you need to go back all the steps so let's turn on the knot,
and let's make a copy of this knot somewhere else by moving the Gumball, and
hit ALT key. Okay and then let me move this guy to this shank and turn the
original off. We always want to keep the original. Just in case you know something
happen alright. So we need to know how to arrange this one to that one, and how many of
them, so the way to do is go into the "curve" you have "curve from the object" and
then you have "create UV curves" okay so we're gonna pick up this interior on the
bottom, and then we want to create a UV curve from there. Let's pick up so this
is the area that's take a look on the top view this is the area showing if
the interior flatten out, and that's the area you can have a design. So I'm gonna
have my knot scale it down. put it right there and maybe you can adjust to any
angle that you like. Maybe I'll just keep that. That's kind of interesting,
and then so somewhere there and what also you can do
is you can always use aline tool to make sure they are right in the center.
so actually I do want to move it a little bit more of like this.... maybe a
little bit more. okay now we want to take a look how many they will be coming out
so that's do the "array" and "liner array" we pick up our object. I'm
just gonna set it for 12 I think it's volleying enough all right
starting from the end point and then you want to make sure they're overlapping
just a little bit, so you have something to Boolean once you want to boolean them.
okay so yes we have more than enough and it's actually come out really good. it's a little bit hanging outside of this box and that
hanging part well coming into here, so it will look more like a continue
piece, okay so that's a good arrangement. and let's take a look how we make it
back to this ring. Next step, let's see how we can make those design back to the
ring shank so first of all we need to make a reference surface to reference
this surface that we had a UV from. so I'm going to use the command
it's called "surface form planar curve" and then pick up this curve hit ENTER.
So then you will get this surface right there. I'm going to turn the surface into the red color so it's easier for you to see.
now this is red colored surfaces refer to the surface on the ring shank. In this
case the surface is actually cutting a lot of a model and then you won't
actually want all the model to show up so that's going to the perspective
and then you're gonna move it down a little bit so that way you can see all
the link clearly. Okay so kind of adjust to the position see how you like it now
let's go back to the perspective. if you pay a really detailed attention to
this ring, you're going to see a very dark line right there. That is
not because there's a curve there. That's because that's a seam of our surface.
so that means that seam right there is equal the seam right there on
our surface. okay so we need to make sure that the seam is when we click is this
corner compared to this corner right there. okay so let's go to the command is
under the "transform" and you have "flow along surface"
okay so it asks you what do you want to flow? so we're gonna pick up all the
objects that we have design on the flat surface, okay and enter your base
surface. that's pick up this corner right there, and then target surface we want to
pick up this corner, and let's see how it flow. okay so it might take a while
depends on your computer... see how strong it is, but you kind of see this is
actually becoming really well connected is overlapping a little bit and that's
exam all of them, and then they all look really nice go over there, so let's take
a look on the render view. so it kind of stretch a little bit right
there it's because we have this curvature so whatever you flow back it
may stretch a little bit, which is pretty good for our purpose. Because it is a
knot. it supposed to look nature. okay so this is the tutorial for today- how to
make a knot and how to make the knot pattern into the ring. I hope you enjoy
the video please like and comment and share my video that
will be a great help to me. even write it down I like this video, that's helping me
on my YouTube ranking thank you and I will see you next Monday
