Hi everyone, I’m creating a low-poly 3D helmet model intended to be built from 250–300 GSM paper using Pepakura Designer. I’m generating the model as an OBJ file with an MTL file for materials. I’m facing a few problems and would appreciate some help understanding what is causing them. 1. Missing edges in the 3D view My helmet has multiple flat polygon faces with different angles. In shaded mode, the faces appear distinct because of the lighting, but when I turn off the lighting or shading, many face boundaries are not visible. Only some edges appear to be displayed. 2. Missing fold lines in the 2D unfolded pattern When I import the OBJ into Pepakura Designer and unfold it, the 2D pattern often shows only the outer outlines of the pieces. The internal fold lines between individual polygon faces are missing or not displayed as expected. 3. Missing glue tabs Some parts, particularly the mouth/chin section, have no visible glue tabs along the edges where they should connect to the neighboring helmet panels. This makes it difficult to assemble the helmet physically. 4. Interesting difference between OBJ and STL When I export the same model as STL and import it into Pepakura, the affected part gets glue tabs. This makes me wonder whether the problem is caused by the OBJ import, edge interpretation, mesh structure, or Pepakura settings rather than the overall shape of the model. My goal is to generate a clean, low-poly helmet with clearly defined polygon boundaries, correct fold lines, and usable glue tabs, with as little manual cleanup as possible. I’m planning to use Metasequoia for mesh inspection and editing, and Pepakura Designer for unfolding. My questions: Why might Pepakura interpret the same model differently when imported as OBJ versus STL? How can I ensure that every intended polygon boundary is preserved and appears as a fold line where appropriate? Is there a particular mesh structure or export setting that works best for low-poly papercraft models? How can I ensure that every intended connection between separate pieces receives an appropriate glue tab? I’ve attached screenshots showing the 3D model, wireframe, and unfolded pattern. Thanks for any guidance! this is in blender. above image is without light. so all faces are gone. above image shows no visible fold lines for faces above image having no flaps for connecting to above part, while other parts have no connecting to it. https://preview.redd.it/oatyvgawn1yh1.png?width=694&format=png&auto=webp&s=4375da1c862c2330cb8dc5bc7b799b2ec00cee01 https://preview.redd.it/34n9kt7yn1yh1.png?width=653&format=png&auto=webp&s=83d2f941148cb3ffb34a97ef6d37316677b26c7b   submitted by   /u/leyermo   to   r/Pepakura [link]   [comments]