Importing Static Assets - Unity for Absolute Beginners - page 185

7. Click the Console tab (next to the Project tab) to examine the warnings

(Figure 4-41 ).

Figure 4-41. The Lightmapping warnings for many of the objects

Most of the objects are reported as missing a secondary set of UVs, or mapping coordinates. In the
case of the garden structures, the texture has been tiled to increase detail without creating a very
large texture map. In Lightmapping, each face must occupy a unique place on the texture map, as
each has its lighting calculated individually (Figure 4-42 , left). Pieces that overlap or spill over the
edge of the map will fail this requirement (Figure 4-42 , right).

Figure 4-42. A valid Lightmapping layout (left), and invalid layout (right)

If you are a 3D artist, you may be familiar with the unwrapping process and UV unwraps in general.
If not, don't worry. One of the import options is to generate a second set of UVs. These will
automatically be laid out correctly for Lightmapping. Unity, in case you are interested, supports only
two sets of mapping coordinates. Let's see about fixing the CornerGarden asset.