3D Digitizing and 3D printing: Recreating "reality" with "virtual"

Topic background

In recent years, we have often heard the term" 3D ". 3D is considered magical, largely attributed to our high-tech digital means, so that the objective world of 3D entities can be in the virtual world of high-precision reconstruction (3D scanning), free editing (3D design), realistic high-definition display (3D display), and even return to the objective world (3D printing).

    The head photo of Emma's helper arm, which is modeled with three-dimensional software solid edge, is done with 3D printing.

Wu Huaiyu

3D printing, one of the rapid prototyping techniques, It is a technology based on the digitized model file, which uses the materials such as powdered metal or plastic to incrementally construct the object by layer-by-level printing and superposition. 3D Digitizing and 3D printing is a pair of twin brothers, complementing each other.

3D digitization is the premise and foundation for 3D printing, otherwise" Paddle ", while 3D printing makes 3D digital". "

what is 3D digitizing

3D digitization is the use of computers to generate digital 3D drawing models, For output to a 3D printer. There are two types of methods for digitizing 3D. The first category is the use of 3D design software, designers from scratch to design 3D digital products. At present, 3D commercial design software is: SolidWorks, AutoCAD, 3DS Max, Maya, Rhino3D, ZBrush and so on. In addition, there are a variety of unique free design software: Blender, Tinkercad, 3DTin, SketchUp, and many of them also support WebGL-based online editing network.

Of course, not everyone has the ability to design 3D shapes themselves, Therefore, the second type of 3D digitization is 3D scanning (commonly known as 3D photography), based on computer vision, graphics, pattern recognition and intelligent systems, optical and electrical integration control technology to the actual existence of the 3D object scanning acquisition, in order to obtain realistic digital reconstruction. 3D scanning technology is divided into active (active) scanning and passive (Passive) scanning two kinds.

active scanning is the addition of projected light to the object under test, including laser, visible white, Ultrasound and X-ray, etc. The laser line scanning can scan large objects, but because only one light is projected at a time, the scanning speed is slow. At present, the newest scanning equipment based on structure white light can measure one face of the object at the same time, the point cloud density is large and the precision is high, so it has a unique advantage in acquiring three-dimensional surface information quickly. There are also light-coded scanning devices, such as the Kinect released by Microsoft in 2010, with real-time features.

passive scanning does not emit any light on the object under test, Instead, the cost is very cheap by capturing the reflection of the ambient light on the surface of the analyte, which does not require special hardware. Passive scanning reconstruction techniques, such as Autodesk's newest 123D Catch, are usually based on a computer's three-dimensional vision theory, such as stereo vision methods. Due to the influence of environmental illumination on image quality, passive scanning often has lower accuracy and higher noise error.

After acquiring the original data of 3D scanning, it is often necessary to deal with it in complex , such as aligning and stitching the shape fragments of multiple angles of view to unify in the same world coordinate system. In addition, bug patching, noise removal, triangulation, and re-meshing are needed to produce the final high-quality watertight surfaces.

There is no mature 3D digital technology capable of fully automatic real-time reconstruction of any shape in nature, such as for human hair. Therefore, in the actual operation process, often need to combine a variety of scanning technology, as well as a certain manual editing, in order to obtain a good quality of reconstruction.

help 3D printing

3D Printing was born in the 80 's, Used to transform a complex 3D digital model in the virtual world into a real 3D entity in the objective world. Unlike conventional "cutting material" machining techniques (such as 3D engraving), 3D printing uses a "layer by step" approach to generate 3D solids. 3D printing requires no machining or any tooling, which greatly reduces the difficulty of manufacturing complex products and shortens the development cycle. At present 3D printing in film production, game animation, medical, education, architecture, archaeological relics, production and manufacturing industries have played a unique role.

3D printing has become a hot news in recent years, It has nothing to do with the release of the UK RepRap Open source project in 2006. RepRap is the cornerstone of the development of 3D desktop printing, which directly spawned a large number of cheap and popular 3D printers, including MakerBot, ranging from thousands of to tens of thousands of yuan.

and in the field of high-precision large-size industrial printing, US 3D Both systems and Stratasys have accounted for most of the market share. Of course, in this new technology competition in the field of fierce challenges, such as Mcor company in 2012, the new Iris full-color printer, just ordinary A4 office paper as raw materials, with ultra-low cost advantages and green environmental advantages. At home, China's 3D Printing technology Industry Alliance was founded in 2012 by the Asian Manufacturing Association, Huazhong University of Science and Technology, Beihang University, Tsinghua Univ. and other research institutions and enterprises.

At present, 3D printers have been able to use a wide range of new materials (liquids, Powder, plastic wire, metal, sand, paper and even chocolate, human stem cells, etc.), through the ink-jet deposition, melting deposition molding, laser sintering, stereo lithography and other processes will be three-dimensional digital model into the physical, from toys, tools, kitchen supplies, architecture, fashion clothes have everything, and even directly printed with the touch of artificial ears, Human skeleton, people fake teeth, fresh meat, as well as * *, sports cars, unmanned aircraft and so on.

3D printing technology is currently facing the following major issues to be addressed urgently:

First, compared to conventional cutting technology, Product size accuracy and surface quality is relatively large, product performance is not up to many high-end metal structural parts requirements. Second, mass production efficiency is relatively low, can not fully meet the needs of the industrial sector. Finally, the cost of equipment and consumables for 3D printing is still high, such as metal powder-based printing costs far higher than traditional manufacturing.

This shows that Although 3D printing technology is a revolutionary breakthrough in the traditional manufacturing technology, but it can not completely replace the cutting, casting and forging and other traditional manufacturing technology, the two should be a mutual support and complement, the common perfect and development of benign cooperative relations.

The advantages of combining 3D digitization with 3D printing technology, It is not only to restore the real world by means of reproduction, but also to create a better world on the basis of 3D digitization and redesign work.

In the case of the film Avatar, Many beautiful scenes cannot be photographed directly from the real world. And through the digital art design, and then the use of 3D printer directly printed out, so not only to eliminate the time-consuming laborious hand-made, but also to achieve a realistic effect beyond reality. The perfect combination of 3D digitization and 3D Printing will realize the new realm of "virtual" reengineering "reality".

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Transferred from the "Solidedge Union" public number.

3D Digitizing and 3D printing: Recreating "reality" with "virtual"