9.5.2

960 • CHAPTER 18
TEXTURE MAPPING • 961
A new UVW tag is added to the existing ones each time you call Generate UVW Coordinates. A Texture
tag (UVW mapping selected) always uses the UVW map directly to its right in the Object manager.
This allows you to assign different UVW maps to different Texture tags. If there is no UVW tag to the
right of the Texture tag, then the rst UVW tag will be used.
What is the structure of UVW coordinates? Imagine a grid divided into a U direction and a V direction
(see Figure 1, below). The UV range starts at 0, 0 and ends at 1, 1. For an upright polygon, 0, 0
describes the top left; 0, 1 the bottom left; 1, 0 the top right and 1, 1 the bottom right. A texture is
stretched out between these four coordinates (Figure 2).
Figure 1. Figure 2.
But where is the W coordinate in this system?
Recall that conventional textures are two-dimensional — the W coordinate is created only when
needed. Once created, the W coordinate behaves in the same way as the UV coordinates.
Selective UVW Mapping
CINEMA 4D has two ways of allocating texture projections to polygon selections (rather than to the
whole object as described above). The rst method is described below. For details on the second
method, look up ‘materials, restrict to selection’ in the index.
Selective UVW mapping allows you to apply a different projection type to several regions of the object
using the same texture geometry. Proceed as follows:
 Create a sphere and convert it into a polygon object using Make Editable.
 Create a new material with a texture, e.g. the checkerboard shader, and set
the projection to Flat.