A 3D model is a digital representation of an object using points in a 3D space that are connected by geometric entities. All of the points, shapes, and lines create a 3 dimensional object. A 3D model occupies the X, Y, and Z planes whereas a 2D object only occupies 2 of the 3 planes. In other words, a 3D model has a measurable height, width, and depth.

There are a number of ways a 3D model can be displayed, both digitally and physically. 3D models can be displayed digitally as an image with 2 dimensions through a process called 3D rendering. Or, 3D models can be displayed using computer simulation. A computer simulation of a 3D model can be rotated and viewed from various perspectives.

A third option to view a 3D model is to physically create it using a 3D printer, CNC machine, or other method that creates a tangible object from a 3D model. A tangible object provides perspectives and insights that are impossible to discover with a digital model. This is why prototyping an object is a critial step in the manufacturing process.

3D models can be created through a number of different avenues. You can create a 3D model of an object that already exists with a 3D scanner. A 3D scanner is a device that scans an object from many angles and creates a 3D image of the object. This model can then be imported into 3D design software for clean-up and manipulation. 123D Capture is an app that turns a normal camera or your mobile device into a type of scanner. This is something you can try at home for free.

There are many design programs that help you create 3D models. If you create a 3D model through design software, you are only limited by your imagination. There are both commercial 3D (or CAD) programs, like AutoCAD and SolidWorks, and software for the home user. Autodesk offers some free, consumer design programs. Other popular, free programs include Sketchup and TinkerCAD.

A third way to create a 3D model is through mathematic equations, called algorithms. Creating models algorithmically is also known as procedural modeling. A procedural model often has repeating patterns or designs where one part of the design is derived from a previous part and so on.

3D models are used in many different industries including:

Manufacturing - the engineering community uses 3D models for prototyping. With 3D printing, prototypes can be created and tested very quickly. this is known as rapid prototyping.

Medical - doctors use 3D models when building prosthetics, medical devices, and medical models.

Entertainment - both movies and video games use 3D models for special effects and graphics.

Science - very large things and very small things can be studied more effectively through 3D models. Earth science uses 3D geological models as a standard practice.

Architecture - for a long time architects have built scale models to depict buildings. With 3D printing, these models can include greater detail, be in full color, and are less expensive than they have been in the past.

There is a large market for 3D models and related content. With the emergence of 3D printing technologies, this market is expected to grow in years to come.