Seams and stretching

-When UV Mapping there are a couple of important challenges that we need to address. One is stretching and the other is seams. In terms of stretching we need to mindful of the relative proportions of the UV layout to the topology of the 3D model. If the two differ radically then the texture can be stretched when applied back to the 3D object. To test for stretching a temporary checkerboard pattern is used. When the squares of our checker pattern are stretched into rectangles we know that any subsequent textures we apply will also be stretched.

Blender has a couple of test patterns built in for us to use and we'll go over shortly how these are generated. But notice if I move one of the UVs around it will stretch the checkers on the object. If we were to apply an image texture to this, it too would be stretched. The other challenge we face in UV mapping is where we should place our seams. There will always be seams. We cannot avoid them. But we should do out best to hide them from view. We'll need to know our 3D model and how it will be seen in the final render.

So for example if this soup can were on a shelf, the seam could be placed at the back of the object. The more complex an object, the more forethought and strategy may be needed to hide the seam from view. In the next few videos we'll talk about some of the tools Blender provides to help us deal with stretching and seams.