This programming project began when I tried to make a pottery model in paper, as a toy. Then I found making a 3D Unfold app is great not only for CAD users but also for myself to perfect my geometry and polyline programming system.

Important Note: The app can only unfold a 3D paper-like model with flat faces and straight edges. It also doesn't support faces with thickness.

Click the Add-in ribbon tab, and you can see the 7cad 3D Unfold ribbon.

7cad_Unfold command's window has 2 tabs. The first tab is to unfold a general 3D model shape. It is recommended that the 3D model be a decimated 3D mesh.

The second tab is for the case of unfolding an octagon revolved shape. No need for a 3D model here. You only need to specify the rotating curve polyline and the axis.

After the unfold command has done the job, you can run the 7cad_FoldUp command to see how the flattened unfold faces can be folded up and get back to the original. This command will create a block named "Fold Up Animation". Within the block, all animation items are put into layers named "Fold Up Animation 1", "Fold Up Animation 2", ... Click the "Forward" and "Back" arrows to see the animation. This command is for demonstration purposes only.

Finally, it is the 7cad_Cutout command. This command joins unfolded pieces together in union polylines. Print the unfolded layouts to papers, cut the union polylines out, fold up and stick them together, then you can have your favourite real world paper model!

A web version of the app is available here, powered by Autodesk Forge Design Automation:

https://www.7cad-programming.com/06unfold/7cad%203d%20unfold/