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40   DESIGN                                                                       SEP/OCT 2026 FDM ASIA | www.fdmasia.com






         pxhere.com                                          in VR and reproduce the result with ordinary tools, exporting
                                                                Our system bridges this gap by letting users design freely

                                                             the complete set of part dimensions as a single document
                                                             so that the object can be built in the real world.


                                                             System Design & Development

                                                             The proposed system was developed in Unity (version
                                                             2022.3.52f1) for the commercially available, unmodified Meta
                                                             Quest 3 head-mounted display. Development was carried
                                                             out on a PC with an Intel Core i7-14700KF CPU, an NVIDIA
                                                             GeForce RTX 4070 GPU, and 32 GB of RAM.
          and the commercial VR game VRKShop lets users saw and   The system is organised into two functional layers on top
          hammer virtual wood and export finished objects as OBJ files.   of a common object-management foundation. Users interact
            However, these were designed as VR woodworking games   with  the  virtual  workspace  through  the  VR  headset  and
          rather than aids for physical DIY: VRKShop can export OBJ   hand controllers, which provide the input for generating and

          geometry but provides no function to export the complete set   manipulating objects in three-dimensional space.
          of part dimensions as a single document, which would be   The first layer comprises DIY functions that let the user
          required to reproduce the assembled object in the real world.  model furniture entirely within VR. The second layer comprises
            Finally, recent work examines how far mixed reality can   fabrication-support functions that convert a completed virtual
          stand in for physical prototypes when evaluating a design.   object into the information needed to build it physically,
          Wang et al. built mixed prototypes  combining 3D printing,   ultimately producing a PDF blueprint that can be handed to
          interactive simulation, and a head-mounted display for the   an external wood custom-cut service.

          usability evaluation of a handheld printer and found them well   Four functions were implemented on the Unity VR core
          suited to comparing design alternatives, even though their   to support the DIY process itself. The object generation
          absolute values may deviate from the final product.   function lets a user spawn objects of various sizes, shapes,
            Dybvik et al. further showed, using fNIRS, that physical,   and colours inside VR.
          virtual, and mixed-reality prototypes elicit significantly different   Sliders and toggles on a panel set the desired size and
          prefrontal brain activity during evaluation and design modification.   colour; pressing the Spawn button then instantiates an object
            This motivates providing users with accurate, exportable   to the right of the panel. Three primitive shapes are available:
          dimensional information so that a design conceived in VR   box, sphere, and cylinder, using Unity's built-in primitives.
          can be faithfully reproduced and verified in the real world.  Every spawned object carries collision-detection components,

            Prior VR design and CAD tools create digital geometry   physics-simulation components, controller-interaction enabling
          but stop at the edge of the virtual environment; AR tools for   components, and material data defining its colour and
          physical DIY guide the hands but assume a predetermined   appearance.
          artifact; XR in-situ systems couple design and making but rely   The object cutting function lets a user cut an object inside
          on specialised hardware or a specific material; and existing   VR. It is built on EzySlice, a pure mesh-cutting library that does
          virtual fabrication systems are games that do not export the   not itself support cutting inside VR; we therefore used a VR
          data needed to rebuild the artifact physically.    cutting extension as a base and modified it in three key ways.
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