Blender add-on for creating paper models
The script is included in Blender 2.80. Just enable Import-Export: Export Paper Model in Blender Preferences → Addons.
An optional step before start is to mark edges where the model will be cut. From the Properties editor, call the Unfold operator on the selected model. The edges will get marked as Edit mode Seams, you can edit them in any way you like. The script will use the seams you mark and mark some more as necessary.
All the show happens when you choose File → Export → Paper Model. A File Browser appears, which also allows you to change the export settings in its bottom-left corner.
Then (if everything goes well), the script saves the file without talking. In the settings, if you switch No Texture to something else, Cycles' Bake functionality will be exploited to render the images. That may take some time.
The file format is PDF and should be ready to print. If you want to edit the net by hand, you may prefer exporting to SVG and using a vector editor such as Inkscape.
A humble panel is in the Properties panel in Object Data section. Currently it gives you an overview of how the net will be split into parts (aka. islands). It can show one of them directly in the 3D view, highlighted in orange. You can edit the name of each island and give it a three-letter abbreviation that will be used on the sticking tabs.
Official description and a detailed user manual is located at a Blender Wiki page.
More development details may be found in the github repository. You may post feature requests and bug reports there. Or, if you have a BlenderArtists.org account, you may prefer to post to the associated forum thread.
Bug reports and constructive ideas are appreciated. If the script fails or creates something useless, please, let me know, I will try and fix it. Also, if something feels unnatural to you or you need support for a specific task, I will appreciate if you tell me.
The export script can only handle flat faces, whereas Blender allows you to move vertices around freely. If a quad face is not perfectly flat, for instance, the exported net will be skewed and impossible to glue correctly. The easiest option is to convert all faces to triangles before export.
For the purpose of my Add Dual Polyhedron script, I have coded an operator to automatically flatten all faces. Copy the code from the aforementioned thread, install it as an Add-on and then look for a Mesh operator called Planarize. Someday I will perhaps include this operator in the Export Paper Model script as well.
Obviously, people have been using this script for making of paper models. Examples posted on the forum include F-16 fighter plane, a standing tiger (unfortunately not visible to the public), a lying fox, WALL-E, Suzanne, Gormiti head, Tremulous trapper and a wolf head.
More involved use cases include folding out of metal sheets – a full-size human figure, packaging design (in conjunction with the Convert to Armature script), cloth design and architectonic prototyping. (I do not have the rights to publish all the professional usage of my script.)
If you used the script to make something cool, you would be most welcome on this list. Just drop me an e-mail.