## 3 Materials and Methods
### COVE-VR: VR System for Industrial Collaboration
#### 3.2.2 Virtual Tools  
We define virtual tools as virtually tangible elements of VE, which have a function to perform over VE (whether it be the creation of new digital content or manipulation of VEs to facilitate the execution of industrial tasks). Eight virtual tools were created to aid the process of maintenance method development and technical documentation creation.  
The Showroom is equipped with a 3D model pedestal, the so-called (1) _Disassembler_, which allows in-depth investigation of 3D models (assembly/disassembly), including changing their size, rotation, and vertical position via the wall menu. The models can be disassembled into parts, which in turn can also be highlighted or removed.  
All other tools are accessible in both virtual spaces; they are opened via the wrist menu on the left controller. _The Model Placement tool_ (2) allows importing any 3D CAD model in the STEP format to the virtual environment. The models are converted asynchronously in the background by a separate application, which we developed to continuously check for new models placed in the application's directory. The import process in the VR application itself was also made to be as asynchronous as possible, although it still resulted in slowdown and a loading screen was therefore added. Several levels of detail are created, of which the highest is only used for visuals and the lower levels can be used for collision. However, in our case, a simple box collider was enough and significantly faster for interactions in the VE. Colors are preserved, but metadata is not converted, which is a shortcoming of our approach.  
_The TextBox tool_ (3) was designed to create textual notes in VR, which can be used to support asynchronous communication or directly as textual elements for technical documentation. Text can be inputted via speech recognition or virtual keyboard in two languages (in our case study): English and Finnish. Support for other languages could be added as needed. The note can be left as a text box or as a smaller message bubble icon in virtual space. All text notes created in VR are further able to be exported to a file with the author's name, the message number and a timestamp.  
_The Camera tool_ (4) is a multipurpose tool made to allow taking pictures and videos from a virtual environment. All created media files can be accessed from the desktop. In addition to regular photo and video modes in front- or back-facing mode, with or without a timer, the tool also supports outline rendering, which captures only the line art in black and white.  
_The Measure tool_ (5) was added to allow taking measurements of the dimensions and distances required for maintenance method creation. To lock the movements of 3D models and measures over grid points, the _Grid Snipping tool_ (6) was created. The grid size can be adjusted. With _the Delete tool_ (7), 3D objects and other tools can be removed from a virtual  
Figure 4: Working virtual environments: (**a**) the Lab VE, which replicates a real elevator shaft and (**b**) the Showroom VE with a disassembled 3D CAD model.  
environment. Finally, the _Save World State tool_ (8) is used to save all created content in the VE, or to load an existing state, for example, one left by the previous worker.  
In summary, our virtual tools were designed to fulfil industrial needs: to advance department-to-department communication and to enable digital content creation for maintenance documentation. At the same time, the tools are generic enough to support many other industrial use cases that were not considered here.