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RHINO TUTORIAL #2
USING RHINO TO BUILD A SCI-FI CHAIR
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This is a basic tutorial
on Rhino, explaining some simple functions and tips to help you
:)
Note there are usually many ways to accomplish the same thing in
Rhino using NURBs, this is just one way. |
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#1
I'm going to make the chair back legs in standard fashion
and supporting the "back". I start with a square curve
to create the cross section of this tall back piece.
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#2
I don't want it to have square, ugly edges, so I use "fillet
curves" to round the corners. When done, I "Join"
them into one solid curve
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#3
Next I make the curve that will define the height and bend of
the back piece, it has only 3 points, which is fine, I can alter
the middle one easily to change over all shape.
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#4
Now, to make the piece, I need a curve for each end,
which will "flow" along the main curve to create a solid
object.
For precision, I wish the to top curve to be at the same angle
as the main uipright curve, rather than just cheaply squared off
horizontally.
To do so, I use "Transform, Orient, Perpendicular to curve",
so the curve is at 90 degree to the curve, regardless of how much
the curve bends.
And here it is
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#5
Now, I connect the two end curves, flowing along the upright curve,
using "Surface, Sweep to 1 Rail"
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#6
Once I've got that done, I make a simple elongated
cube, to be the horizointal support of the seat. So that it mates
up neatly with the upright at the back, I boolean it, cutting
it neatly. I could use "split" but that slices the end
open and leaves it open, which I don't want as I wish to round
the parts where the objects meat, using "chamfer", for
which I need a soild object.
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#7
This is the chamfering being set. I could use "fillet"
for a rounded end, but I just wish an angular, chiselled effect
so I use "Chamfer" command.
And this is the result
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#8
Next, I will make a short upright to support the front
of the seat. I'm going to make this look sort of like it's been
turned out on a lathe. To do this I make a curve to describe the
profile of the object
And then I use "Surface, Revolve" to spin that curve in
a circle, much like using a lathe.
This is the result
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#9
Hm, it's too broad at the top, it will get in the
way of the user's knee. No problem, I'll narrow just the top
part of it!
Surfaces in rhino, as opposed to solids, can be deformed using
"points". I turn on Control Points.
I then take the points at the top on the outer and inside edges,
these define how the top is shaped., and scale them in to the
middle, pulling the top into a flatter shape.
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#10
I'm going to blend the horizontal part to this ornate end, to make
it look more organic. I start by making a cube object, slightly
larger than the horizontal piece, then using that to "Split"
the rounded end. I need it bigger, because I wish the surfaces to
blendin an arc, not a straight line, so one must be bigger than
the other.I also Split the end off the horizontal support using
the vertical support, as blending need open surfaces, not closed
solids. It's liek making a joint between two pipes using a htin
sheet of steel, can't do it if it's a solid bar.
an important point in doing this is to start the initial points
in a good spot, I use "snap to point" to make sure
both start evenly. Then use Preview, and tweak it to it's good.
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#11
Next I wish to make a back piece to join the sides
for support and comfort. I decide I'll make a zig-zagging pipework
to go with the sci-fi look. There's many ways to do this, what
I did was copy the curve used to make the original upright,
so I have three curves: 1 middle, 1 each side. I'm going to
split them into even pieces, so I can connect curves to them,
giving me a curve that follows the shape of the upright's longtitudinal
curve. The ends of each split curve will give me something to
attach my curve to the pipe, sort of like playing "connect
the dots" ;)
I make lots of simple surfaces, then Split the 3 curves
Next I make a curve that connects ot the end of
these curves using "Osnap, End" with "Project"
turned off (or it will project onto a flat plane on the floor,
which I don't want, I want it to be follow the curved back)
Once that is done, I use "Pipe" command,
then I make another simple surface to split the bottom off neatly
I add a couple of shheres and scale them down in one axis, to
flatten them and cover the ends of the pipe.
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#12
Now to make the seat, I am going to make a sphere, flatten it,
and boolean off the ends
Flattened and scaled:
Next I make a curve, extrude it into a surface, and
use that to boolean the end off, giving a nice rounded end. I
do the same to the back. With surfaces, it's important to check
the direction of the UV's as that tells you which side they will
boolean to, you can alter the UVs at any time with the "Dir,
Flip" command"
Then I fillet the front edge to give it a more comfortable shape
(just visible as thicker line at front in this shot)
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#13
Final result :)
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tip:
When finished, I will often use "Solid, Extract Surface",
or "Explode", to split important surfaces off an object,
so they can be individually textured later on. |
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