Surfacing - Blender Foundations: The Essential Guide to Learning Blender 2.6 - page 181

or Face select mode, with the switch on the header. You can make selections, then transform them with
the standard shortcuts (G, S, and R keys). In fact, if your Project from View didn't nicely fill the available
space (or perhaps went outside the boundaries of the workspace), select everything with the A key, then
scale and translate the vertices until they fit closely within the outer edges, like the figure.
On the UV Editor's header is a selector for displaying an image, tagged with a “New” button. Click
the image icon to the left of it, and select the texturing image carpet3.jpg that we'll be using for the
floor. When you do, the image is shown in the UV Editor, with the projected mesh as an overlay.
Sometimes choosing an image can alter the zoom of the window, so you may have to roll the mouse
wheel and MMB drag a bit to get everything nicely centered and sized in the window. Now
you can get a sense of how this works: Whatever portion of the image is contained within a mesh
face in the UV Editor will be used for the texture of that same face in 3D.
If you're wondering about the ceiling and walls right now—don't. The material that uses UV mapping
only applies to the floor. If we were UV mapping the walls as well, we would have to take some additional
steps, but for now we're just getting familiar with the UV Editor and our simple overhead projection will
work fine for the floor.
Get yourself back to the materials and texturing screen, where we'll deal with the scale of the texture.
Looking at the carpet texture with the mesh overlayed in the UV Editor, it was pretty obvious that our
carpet image is the wrong scale. Applied to the floor like that, it would look horrible. You already know
two ways to adjust the scale of a texture: the Size control on the texture's specific style panel, and the
XYZ size controls on the Mapping panel. However, we don't just want to decrease the size of the carpet
image in the texture space. Unlike procedural textures that extend in every direction for infinity, image
textures have a definite and obvious end point. If we reduce the image too much (or at all, depending on
the mapping), there will be places in the mesh that don't receive any texture information. Blender handles
this by repeating the image over and over in all directions. So, if you shrink it using the XYZ size controls
on the Mapping panel, Blender will happily fill in the empty space with copies of the image.
That's the default behavior, but you are by no means stuck with it. The Image Mapping panel provides
the controls for dealing with this. Figure 7.14 shows a close-up of the panel. The Extension menu decides
whether to Repeat the image, Extend its edges to fill in
empty space (useful for pictures with a solid color border),
Clip it (leave the empty space empty), or to even use it as
a checkerboard with another image texture. With Repeat
chosen, you can easily specify how many times you want
the image to repeat within the texture space. When working
with UV mapping, the texture space is the entire UV space
as shown in the UV Editor. So, how many times do we
need to repeat the carpet image across the floor to achieve
the correct scale? Trial and error with test renders indicated
that the number was six. And, since the room was square,
I chose six for both the x and y repetition. A rectangular
room would have required different values.

Figure 7.14 The Image Mapping panel.