It's one of the best script i ever seen - free for commercial use and with power of hammer and full of helpful features. Roofs, tiles, floors, walls, complicated systems of blocks - now it easy:) Just use this script and use it to create real 3D roof (presets are included to script!). You can cut your filled walls in angles which you can define for every edge, you can define area (by spline) to fill it with your own component, you can change everything in real time. Here is script:
http://www.avizstudio.com/tools/atiles/
And check a video tutorial about it:
Check their ATree3D script too (free) :
http://www.avizstudio.com/tools/atree3d/
