The other day I found a link to Google SketchUp. I downloaded it and started to draw.
The picture above is a crude representation of what you can do with SketchUp. I am not an artist, and it shows. However, if you are, and spend the time, there are some very powerful tools in SketchUP that can allow you to design some very impressive 3-D drawings.
Check out their web site for more information. They give you about 400 minutes of trial time, and after that it will cost you to use.
It is not as easy to use as the demo video's make it seem. You will have to practice to get really good. And I suspect you will have to have some artistic ability as well, but, I may be wrong.
See the different views of my "Dream House" (geeee, I must be falling on bad times if this is my dream....). If you look carefully, you can see a person in the house. The windows become transparent....really cool.
Enjoy.