CGCookie – Building Custom Transform Nodes in CyclesThis course covers how to create custom mapping and transformation nodes in Cycles, including the math and theory behind vectors.

Blender’s default mapping node allows simple transformations of texture coordinates, but there are a lot of cases where more flexible inputs and non-uniform transformations would be incredibly valuable.

By the end of the course you should be quite comfortable with manipulating textures in Blender and have a working knowledge of what Cycles is doing with them behind the scenes.