Please read forum rules before posting. This thread does not belong here, and you're much more likely to get help with your questions in the correct forums.

1) If you would like to know about making your computer run the Sims game better, you need to check out the Computer & Software Technical Support forum. Your questions about graphics can all be answered there.

2) If you want help with creating content for the games (building, making new objects or recoloring, etc), you need to check out the 'Create' section. There's lots of tutorials there, but if you still have specific questions after reading the tutorials you can feel free to post in the forum.

Without having seen the video, it *sounds* like they probably used the "individualroofslopeangle" cheat. Try opening the cheat console and typing

help individual*

into the box. [I may have misspelled "individual", though, so spell it right if I did. ]