The benefits of 3D laser scanning include:
- Increase effectiveness working with complex parts and shapes
- Help with design of products to accommodate externally designed and old parts
- Replacement of missing or old parts
Scanning Process
Our specific 3D laser scanning tool is the ‘Handyscan 3D’, which is a modern day laser scanner which uses the VXScan software. Its net worth is around the thirty-five thousand dollar mark. It gives its user the complete flexibility to obtain the scan of a 3D object fast.
It operates using two stereoscopic cameras and a laser in the middle. The laser is projected onto the object which is then reflected of the special reflective target(black/silver dots) placed around and on the surface of the object. The software running in the computer uses these targets as a location reference points to calculate its position in the 3D space. Thus creating a computer generated image of the object on screen.
The surface, the laser and the cameras form a triangular path, much like the GPS, which refers to the beacons transmitted by positioning satellites. The VXScan software allocates a coordinate to each registered point. Using this principle, tens of thousands of points are scanned each second, thus helping generate in real time a rendering of the surface. This helps the user to manipulate the object and move it during the scan.
Although there are a few guidelines to use the scanner, it is fairly user friendly and quite easy to use:
- It needs to be a distance, preferably 10-15 cms away from the object for the triangle to be created.
- It has to be moved slowly around the object.
- The surface need to be as non-reflective as possible. The scanner seizes to work on any smooth, polished surface.
- Familiarise yourself with the operation of the Handyscan laser scanner and its associated software running on PC before starting. Some quick trials might be necessary to see if you can make the model. Ensure that the model generated can be read by a CAD software such as CATIA.
Case Study
3D scanning has many applications in the real world and most of which people would not associate 3D scanning with, 3D scanning is sometimes used in the creation of movies and video games were an artist would create a physical model of an object or even a character in the game and then scan it in, this can save time as it is often quicker to create a physical model than it is to make a digital one with computer modelling. Another common use for 3D scanning is historic replication of objects that have been found, for example a dinosaur bone that maybe very rare could be scanned and a replica made of it for scientific reason or for museum use in displays were it may be not safe i.e. the artefact may be very fragile or maybe if there is only one of that object, replication for other museums. Reverse engineering is another common area were 3D scanning is used, were if you have something that you would want to replicate but do not have the specific dimensions for you could simply scan the object and then either use a 3D printer to create the object or use other manufacturing methods.
Conclusion
In conclusion through the use of a 3D laser scanner we are able to analyse real world objects or environment to collect data on its shape and appearance, which can be used to construct digital three-dimensional models. Although 3D scanners do have its limitations such as difficulties to scan when the surface us shiny or mirroring and its expensive cost, the technology can be used in many effective ways to help the society such as medical research.
As we scanned the item, Data was collected by a computer and recorded as data points within Three-dimensional space, with processing using a computer this can be converted into a triangulated mesh (many triangles together forming the image scanned) and then a Computer-aided design model. Although the CAD image was not perfect, with the use of an editing program we were able to make it as accurate possible to the original product scanned. Even though this was done, it was still not perfect. We also learnt that the 3D laser scanner had to be moved around the item slowly and in an angle following what the direction instructed on the computer. Overall we enjoyed using the 3D laser scanner and look forward to using such a tool in the future.
References:
Yu, F, Lu, Zheming, 2010, ‘Three-Dimensional Model Analysis and Processing’, Zhejiang University Press, Hangzhou.
Chen, T, 2009, ‘New 3D Scanning Techniques for Complex Scenes’, VDM Publishing, New York.
Nuchter, A, 2009, ‘3D Robotic Mapping’, Springer, Berlin.