Google SketchUp is a free 3D-modeling program,let you explore the world in 3D.
Editor: Google SketchUp is a free, easy-to-learn 3D-modeling program with a few simple tools to let you Create 3D models of houses, sheds, Decks, home additions, woodworking projects, and even space ships. You can add Details, textures, and glass to your models, and design with dimensional accuracy. You can place your finished models in Google EARTH, share them with others by posting them to the 3D Warehouse, or print hard copies. Google SketchUp is a great way to discover if 3D modeling is right for you.

By matching to a photo, you are able to create a 3D model by tracing a photo or matching an existing model to a background photo. Matching to a photo allows you to designate lines in a photograph that correspond to the axes in Google SketchUp. Then SketchUp calculates the camera position and field of view to equate the modeling environment to the photograph. You can also apply photos to one or more model surfaces or link photos taken from different viewpoints to re-create multiple sides of a building. you can free download Google SketchUp 6.0 now.