NURBS and Meta Shapes
11
11.1 Using NURBS
11.2 Creating a Lofted Tunnel
11.3 Meta Shapes
11.1 Using NURBS
When you press Shi + the A key and select “Add,” you will notice other object
types besides meshes, cameras, and lights that can be created. One other type of
object that can be created is a surface (NURBS). NURBS stands for Non-Uni-
form Rational B-Spline, which means its a type of editable curve or surface that
can be converted to a mesh object. If you look at the “Surface” menu, you will see
a variety of shapes that can be created. ese shapes can be used as they are or
converted to meshes so you can work with vertices. To get you started and give
you an idea of how this is achieved, follow the procedure outlined below.
Start a new scene in Blender and delete the default cube. Place the scene in
top view (number pad 7) and add a NURBS circle (Shi + the A key – “Add” –
Surface” – “NURBS Circle”). e NURBS circle will be displayed in the scene
in object mode (Figure 11.1).
Tab to edit mode and you will see the circle surrounded by manipulation
handles, which by default are all selected (Figure 11.2). Deselect the handles
using the A key and right click on a handle to select it. If you have the manipu-
lation widget turned on, you can use it to move the handle and deform the
circle (Figure 11.3). Alternatively, you can press the G key and drag the mouse.
Tab into object mode to see the deformed circle (Figure 11.4). e defor-
mation may be what you want or you may wish to further rene the shape.
Figure 11.1
Figure 11.2
186 11. NURBS and Meta Shapes
You can do this by converting the NURBS shape
into a mesh object. With the shape selected in ob-
ject mode, press Alt + the C key and select “Mesh
from Curve/Meta/Surf/Text” in the drop down
menu (Figure 11.5). We are converting “Surf” into
a mesh object. Obviously this same command is ap-
plicable to converting “Curve,” “Meta,” and “Text”
into a mesh object.
Tab to edit mode and you will see the shape now
has vertices applied that you can select and manipu-
late to further modify the shape (Figure 11.6). e A
key will deselect the vertices you have just moved and
pressing the A key again will select all the vertices.
Tab to object mode then press Alt + the C key; this
time select “Curve from Mesh/Text” (Figure 11.7). is
option creates a mesh curve object from the mesh ob-
ject. Tab back to edit mode and you now have a curve
Figure 11.3
Figure 11.5
Figure 11.6
Figure 11.4
Manipulation widget
Vertices selected Vertices moved
Deformed circle
18711.2. Creating a Loed Tunnel
circle object. You can use the “Geometry” values in the properties window – “Object Data
button to manipulate the object’s shape or select vertices and move them (Figure 11.8).
Since this is a curve circle, it can be used as a path in animation.
is procedure shows that by converting one type of object to another, you have dierent
options for shape manipulation.
11.2 Creating a Lofted Tunnel
is process will take several proles of a NURBS circle, which are all manipulated to dier-
ent proles, and connect them together to form a hollow object (tunnel).
First, create a NURBS circle as described in Section 11.1. e circle is entered in the
scene in object mode, so you need to tab into edit mode. Select the points and shape the
circle a bit. Aer shaping, go back into object mode and change your view so you are look-
ing down on the circle (number pad 7). Use Shi + the D key to duplicate the circle several
times and position them accordingly, then rotate your view so you can shi select each
circle. In edit mode, edit the shapes. Aer shaping the circles, exit edit mode and select all
the circles by RMB clicking on them while holding Shi. Join the circles together, pressing
Figure 11.7
Figure 11.8
Single vertex selected and moved

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