Pepakura Viewer is a viewer that shows and prints 2D patterns in .PDO format. PDO is a proprietary format from Pepakura Designer. This program is able to load 3D patterns and convert them to printable 2D patterns that, when assembled, will produce 3D objects, made of paper. Or save 3D .pdo files, that can be printed with Pepakura Designer or Pepakura Viewer.
Pepakura Viewer will print a pattern with folding and cutting marks, and tabs where you will need to apply glue. This program doesn´t create models, nor it is able to convert from other formats. It just loads and prints .pdo files. Pepakura Viewer shows you the 3D model on the left of the screen, and the printable 2D pattern on the left. You will be able to see the 3D model in arbitrary angles. If you click on a part of the 3D model, it will be highlighted in the 2D model. This will help you in assembling the model. Pepakura Designer owners don´t need this program, since every feature it has is already included in the major program. This utility will be helpful for people that don´t own the program. They can can just download the .pdo model files from the Pepakura Gallery.