3D Scanning is the process involving the digitalization of an object, environment or model in order to obtain a digital 3D model that can be used in a CAD (computer Aided Design) software.
3D scanning has evolved and several technologies exist to obtain 3D data from a real object, most of these technologies rely on light and how it projects onto an object, others are contact-based. Below is a brief explanation of each:
- Laser 3D scanning: this scanner projects a laser ray (it can be a single point or a laser line) onto a surface and a sensor measures the distortion and angle of the laser light reflection, with this information a software triangulates the points and processes the obtained data.
One of the main disadvantages of this technology is that its accuracy depends of the surface properties, if the surface is too glossy or shiny, it will affect the amount of light reflected and can result in errors on the final 3D object.
- Laser Pulse: this process is based on the time it takes a laser ray to bounce off a surface. The laser ray is projected on a surface and collected by a sensor. The travel time of the laser between its emission and reception translates into the surface’s geometrical information, because the speed of light is known we can determine the exact distance between the object and the light source.
- Light 3D scanning: this technology measures the distortion of a light pattern on a given surface to scan the shape of a model or object, this method doesn’t need a laser light, instead the light usually comes from a projector which lays a series of linear patterns or a randomized dot matrix onto the desired object, this information is recollected by a camera or visual sensor.
- Photogrammetry: is a method based on photographies, it reconstructs a 3D subject from photos of the static subject in different angles and with a geometry algorithm performs the process of obtaining a detailed 3D model. This operation requires computer processing time and power, this method outputs a 3D model and its texture (the detail of colors corresponding to the given surface).
Software like Autodesk 123D catch is a good starting point for anyone interested in the subject.
- Contact-based 3D scanning: this method relies on sampling of several points on a surface, measured by the deformation of a probe or sensor through physical touch, the amount of points sampled per area determines the resolution of the final 3D model.
Where art meets technology
Sculptures and statues are an important part of visual arts, this branch focusses on three-dimensional objects and that in most cases have details that can be observed in almost every angle.
Now a days, it’s fairly easy to find an online 3D model of famous statues that can only be seen at museums, and this is thanks to 3D scanners, some of the models found online where the result of an $20,000 piece of equipment, others may have not been as sophisticated or complex but still were able to deliver a fairly usable 3D model. Anyway, these 3D models can be processed to later be materialized with a 3D printer, the scale of the final result will mainly depend of the printer’s capabilities.
Other application for scanning sculptures and statues and the uses for those 3D models are:
- Digital archiving: having an archive of 3D models occupies virtual space instead of physical space.
- Virtual restoration: this can help reproduce broken or deteriorated pieces of art and culture.
- Inspection and restoration for cultural heritage preservation: to help the future generations get in touch with their roots and heritage.
Source: Personal experience and training.