Blender is an open-source 3D modelling software used for creating 3D graphics animation. Most of the engineers and designers will have to work with CAD at some point of time to design objects in a better and realistic way. There are many types of CAD software that they could use like 2D CAD software and 3D drawing software. These free 3d software download are free to use and can be used for many purposes. The tools will be advanced enough to render any object in a realistic way.