One subtle and frustrating anomaly of Sketchup that applies to textures, is the behavior of custom axes. If you build a rafter on a roof plane and then group it or make a component, its axes will align with the default axes, which means the axes will not follow the "length" of the rafter. However, if you use the axes tool to change the axes to follow the roof plane BEFORE grouping or making the component, then that component or group will inherit the new custom axes when it is created. This is good.
HOWEVER, textures do not seem to honor the custom axes. You would expect that if you changed the axes and then applied a texture, that the texture would be aligned to the new axes. IT WILL NOT. It will still align to the default axes.
This makes for a very confusing behavior. Components honor custom axes when being created, but textures do not. However, textures will honor the COMPONENT's axes, but only if applied after the component (or group) is created. This can lead to some maddening behavior when editing, applying, and anchoring textures on components that have been rotated. It's hard to explain in a post, but I will try to build a sketchup file that demonstrates this weird behavior and post it later.
