SketchUp

SketchUp, formerly Google Sketchup, is a 3D modeling computer program for a wide range of drawing applications such as architectural, interior design, landscape architecture, civil and mechanical engineering, film and video game design. It is available as a web-based application.

SketchUp is owned by Trimble Inc.,a mapping, surveying and navigation equipment company. There is an online library of free model assemblies (e.g. windows, doors, automobiles), 3D Warehouse, to which users may contribute models

It includes a complete tutorial that will help you to learn how to use all of the tools it offers very quickly. The tool includes all kinds of modeling options, ranging from creating basic geometric figures to manipulating vertices and faces, not to mention the texture, lighting and rendering tools

Creating a geometric figure is easy. You only have to draw a square with the pencil tool and drag it with the mouse and it will acquire volume. From then on, it's possible to create windows, doors and all the shapes you can imagine. Of course, you can also choose their color and textures.

If you aren't good at creating your own models, the program also includes a huge database of resources created by community members that you can use for free. It includes all kinds of elements, from vehicles to furniture, including human figures and all kinds of decorative elements.