Digital technologies/3D Scanning
3D scanning is the technology of creating a 3D mesh from some mix of scanning techniques. Most 3D scanners use structured light or laser triangulation to scan what they see and use photogrammetry to create the 3D mesh by combining all the 2D scans together. The mesh can be used to create 3D models of various things and applications. For example, scanning a limb to create a custom prosthetic or scanning components to design a custom case, etc. At the makerspace we have the EinScan Pro X2020 which uses laser triangulation to take 2D scans of an object, and its paired with the EinScan software which complies everything together. Both require the other to work properly but the raw scan files can be imported to other post-processing software as needed.
How does it work?
The EinScan Pro x2020 can be used in a few ways. There's the fixed scan mode, where the scanner remains stationary, and the object is rotated in front of it to get all the sides. Or it can be used in handheld mode, with the scanner being moved around the object and the object remaining stationary. Either way, the software will take all those pictures and create point clouds which can be used to create a 3D mesh of the object. Within the scanning software, light post processing can be done to modify the mesh as needed before exporting it as whatever file type is needed for the next step in the process. This step varies depending on what you are trying to do with the 3D scan.
Files Types
3D scanning by default creates point clouds when scanning. These point clouds are then connected to create a mesh. The raw point clouds can be brought into other software's for post processing, but normally the resulting mesh is the file that is imported and exported between software's. However, directly from the EinScan software, as well as most 3rd party software's, the mesh can be exported as other file types like .asc, .stl, .ply, .obj, .3mf and more. For example, to directly print the model it should be exported as an .stl. However if more post processing was to be done or modified in another CAD(computer-aided design) software it could be exported as a .3mf file.
3D Scanning in MakerSpace
Generally in the MakerSpace, doing a 3D scan consists of choosing a scan type, preparing the scan in the software, prepping the object itself, and scanning the object. The resulting scan can be cleaned up at a basic level in the EinScan software and then exported to a stronger post-processing software for further processing.
What Scanner do we have?
In the MakerSpace, we have the EinScan Pro 2X 2020 from shining 3D. like the other tools in the space it is free to use and the required software's to use it are provided in the
The EinScan Pro 2X 2020 handheld scanner has a scan area of 150 × 120 mm—250 × 200 mm and works at a minimum point distance of 0.2 mm. It can catch accurate details of either small and medium-sized objects: from 3 to 100 cm in tripod mode and from 30 to 100 cm when handheld.
Choosing Scan type
When the EinScan software is opened, a scanning method must be chosen. Either fixed or handheld.
A Fixed scan keeps the scanner stationary while the object is rotated on the supplied rotating plate. A Handheld scan keeps the object stationary, and it is the scanner that gets moved around to capture multiple scans from different angles. For smaller objects the Fixed mode should be used whereas for larger objects, the handheld mode should be used.
Further, there's handheld HD scan and handheld Rapid scan. The rapid scan captures less points per second but captures more scans per second so it will create a lower quality but more complete scan faster than the HD scan.
Overall, they are used in the same way. Stationary object, moving scanner.
Turntable settings
During a fixed scan, the object is placed on a turntable that automatically rotates so that the scanner can capture multiples scans from different angles. The number of steps in the full rotation is user set when prepping the scan. A smaller number of steps takes less time but may result in rougher scan quality (as it has less individual scans to take so less data to use). A higher number of steps will take longer but increase the quality of the scan (as there are more scans to help piece together the overall 3D mesh). A good rule of thumb is to start low around 6-10 and increase the steps as needed if the quality of the scan is too low.
When setting up a object on the turntable, make sure the object is centered on the turn table and is fully viewed by the preview of the scanner. Also verify that is it properly supported to the turntable and that it won’t slip as it turns. If it will, use some sticky tack to temporarily stick the object down.
HDR (High Dynamic Range) Settings
The HDR (high dynamic range) settings alter the level of contrast that the scanner will use to detect an object as it flashes light during the scans. A lower HDR won’t pick up as much contrasting details. There is a preview in the program that shows what will most likely get picked up shown in red that can be used to ensure the object being scanned is properly captured. In short, if there are more colours, a higher HDR should be chosen to ensure they all get properly scanned.