A 3D artist’s work is mostly done on a computer and generally entails creating graphics and animations for applications such as video game software. The work requires a strong spatial imagination and the ability to use a wide range of programs in order to depict forms, light and colours as naturally as possible from all angles. Some 3D artists also work as digital sculptors.

We’re all familiar with the scanning of a two-dimensional document; nowadays, any old home office printer can scan. The 3D scanning of people, animals, and objects is rather more complicated – although here, too, technology is developing rapidly, and there are already hand scanners available that are relatively easy to use. These, though, don’t deliver the high degree of accuracy we at Mentum Replicas require for our reproductions; instead we utilise two other forms of 3D scanner.
First things first though: what is a 3D scanner? Wolfgang Böhler defines it as a measuring tool that uses a regular pattern to automatically determine a surface’s 3D coordinates at high speed and in real time.
Mentum Replicas captures people and animals using photogrammetry. For objects, we use either a structured light scanner or a CT scan.
A structured light scanner consists of a projector and a pair of digital cameras. The scanner’s sensors connect to a computer running image-processing software. During the scan, structured light passes over the surface of the object and the digital cameras capture the pattern of the stripes. The scanning software then works out coordinates that add up to a three-dimensional representation of the object’s surface.
If an object’s geometry means it cannot be captured using a structured light scanner (due to undercuts, cavities or interior surfaces), we perform a CT scan instead. Here, the principle is the same as with computed tomography in medicine, but the results are significantly more accurate. We take a large number of x-ray images from various angles in order to produce sectional images that can then be combined in a 3D file.
For structured light scans, Mentum Replicas works with Christoph Egloff of Scanlabor (www.scanlabor.de), while our CT scans are carried out at General Electric’s applications lab: www.ge-mcs.com/phoenix

Essentially, 3D technologies are about generating and processing data of a spatial nature and thus about representations that are, as the name says, three-dimensional. The 3D technologies employed by Mentum Replicas are 3D scanning; 3D model-making using point clouds and 3D mesh models; surface reconstruction; and 5-axis milling. In addition, we use additive production processes such as LMF (laser metal fusion) and laser sintering.

Used to give a matt finish to a surface, abrasive blasting is a technique in which material (anything from sand to nutshells) is propelled against a surface via a jet of compressed air. Mentum Replicas uses it on small areas of busts, for instance, in order to emphasise the shape of the face.

The term bust is used for a three-dimensional upper-body portrait. There are various types of bust but, generally speaking, a bust shows the head, neck and part of the subject’s torso.
It wasn’t until the Renaissance that sculptors began creating busts as portraits. Previously, busts depicting an archetype such as Zeus or Aphrodite rather than an individual were the norm.
When a sculptor sculpts a bust, artistic interpretation always plays a role, with the artist taking the characteristics of the sitter and abstracting or interpreting them. Rather than being sculpted by digital sculptors, our busts, on the other hand, are extrapolated from the subject’s actual data as captured via photogrammetry. This 3D technology allows us to accurately record the precise details of the face and reproduce them faithfully in the bust. The result is a perfect replica, i.e. a likeness that is entirely true to the original.
Busts have been a facet of the culture of remembrance for many centuries; they are often memorials, an expression of esteem towards a notable personage, installed at the individual’s former place of residence or place of work. The interest in immortalising oneself or a close relation in bust form has significantly declined in the second half of the 20th century, but the personal bust is set for a revival. In an age when the production of selfies is increasing exponentially, there is a growing desire for representations that endure.
https://en.wikipedia.org/wiki/Bust_(sculpture)

A visit to a good sculpture collection (we particularly recommend Frankfurt’s Liebieghaus; http://www.liebieghaus.de/en) soon reveals that there isn’t one standard format for busts. In the main, however, a bust, comprises the head, neck and a variable portion of the torso. At Mentum Replicas, we offer three different bust types: Type 1 (face and neck), Type 2 (face, neck and décolleté), Type 3 (face, neck and shoulder area).

In digital sculpting, the tools of the trade are all computer- and software-based. Unlike their analogue counterparts, the works of a digital sculptor are not created solely by hand but with the aid of machines. The sculpture or bust is either precision-milled from a block of material or created layer by layer via 3D metal printing. Either way, the high-tech production process is followed by manual honing by the specialist metalworkers of our parent company Arnold AG (http://www.arnold.de/en), their dedication, precision and skill ensuring a perfect finish.
en.wikipedia.org/wiki/Digital_sculpting

Often known as 3D artists, digital sculptors use 3D graphics software to create three-dimensional models of objects on their computers; these models can then be saved and sent as digital files. Digital sculptors can work with existing three-dimensional models produced, for instance, via 3d scanning or they can create an entirely new 3D data set, building a model either from scratch or from a two-dimensional document such as a photo of a person or animal.

At Mentum Replicas, the latter approach may occasionally be required. Should we be unable to scan a person for instance, either because they don’t wish to be scanned or because they are already deceased, we resort to a digital sculptor. Working from photos, the digital sculptor would then create a 3D data set, taking into account the subject’s distinguishing features and producing a remarkably realistic likeness. In such cases, Mentum Replicas works with Sebastian Barz, a digital sculptor who describes his trade as “character design and 3D art”:
seb-crea.de

The finished piece of work is usually stored as a .ply, .obj, or .stl file.
https://en.wikipedia.org/wiki/Digital_sculpting

The term engraving is generally used to mean the cutting, carving or punching of lettering or some other form of decoration into an object, the removal of material from the object creating an indented surface.
At our parent company Arnold AG (http://www.arnold.de/en), these traditional skills are still practised by trained specialists and it is to their deft touch that we entrust the engraving of our busts’ eyes. As they cannot be captured via scanning, the subject’s eyes have to be carefully reproduced by hand using original photographs from the photogrammetry process. Our skilled engravers take their cue from aspects such as the light points reflected in the human iris, ensuring the bust is as lifelike as possible.
www.oxforddictionaries.com/definition/english/engrave

Creating a permanent likeness of a loved one, a pet, or an object that has personal significance can be described as immortalising it. Prints can fade and digital photos can be lost forever if a phone is stolen, but a metal replica allows a memory of great happiness or deep love to be preserved – both for yourself and for posterity.

Laser sintering (or selective laser sintering, to give it its full name) allows work pieces or decorative objects to be built up layer by layer. The material, be it plastic or metal, starts off in powder form and is selectively sintered via laser beams. This allows any three-dimensional geometry to be realised, even one with undercuts. Laser sintering is an “additive” production process and is part of the burgeoning field of 3D printing.
Mentum Replicas uses laser sintering for the production of certain kinds of shapes. In general, however, milling is our manufacturing method of choice.
en.wikipedia.org/wiki/Sintering
fkm-lasersintering.de/en/

Mentum is a contraction of the Latin word “momentum” meaning “moment”. Given our aim of allowing you to preserve a particular moment in your life, it seemed fitting to call our replicas “Mentum Replicas”. Each of these replicas is a one-off, as individual as we are ourselves. Whether it’s the pleading look of a family dog waiting eagerly for its reward or a souvenir of a sporting achievement that still lives large in the memory, Mentum Replicas can capture the moment for ever, giving you a true likeness of the dog’s head, say, or an accurate reproduction of the racket that hit so many winners.

Via mining, sorting and cleaning, humankind has been able to turn naturally occurring materials into raw materials and then into processed materials for production. Metals are one such category of processed material (others include wood, glass, ceramics and plastics).

Metals are among the most commonly occurring chemical elements on the planet. The elements classed as metals make up more than 70 per cent of the periodic table and are all found to the left of the diagonal line running from Bor to At. Along this line are the metalloids, which form a fluid boundary between metals and non-metals. Depending on the conditions and the element with which they bond, metalloids can behave either as metals or non-metals.

To be defined as a metal, an element has to have the following properties: low number of electrons in the outer shell, metallic lustre, reflectivity, opacity, (high) electrical conductivity, thermal conductivity, ductility (ability to be moulded).  

With regard to reactivity, metals are categorised as either noble metals or base metals. The former are corrosion-resistant, while the latter are highly reactive. At Mentum Replicas, our particular preference is for stainless steels. Containing a high proportion of chrome and nickel, these iron-based metal alloys offer good corrosion resistance and are easily worked.
www.britannica.com/science/metal-chemistry

A milling machine uses rotating cutters to remove material from a workpiece and thus shape it as required. Milling developed out of drilling but differs in that a mill can work in three or more feed directions, enabling it to produce complex spatial objects.
Milling machines are generally divided into conventional mills and CNC mills. A CNC milling machine can have up to 5 axes and be programmed via computer numerical control (CNC). The axes can either be controlled individually or simultaneously using feeders. With a 5-axis mill, the cutter can be aligned at any angle to the workpiece, allowing extremely complex 3D contours to be realised.

Mentum Replicas produces its replicas using 5-axis milling machines. The cutting process for a single full-size bust takes hundreds of hours. en.wikipedia.org/wiki/Milling_(machining)

In 3D modelling, a spatial object is represented on a computer screen using a three-dimensional system of coordinates (X, Y, Z).

The Greek letter “mu” or “μ” is used to represent “micro” in units of measurement. 1 μm is thus a thousandth of a millimetre (0.001 mm). Mentum Replicas measures people, animals and objects to an accuracy of 50 to 100 μm, or 0.05 mm to 0.1 mm. In practice, this means that, during 3D scanning, the scanner scans every millimetre of the object’s surface 10 to 20 times, combining the many data points thus acquired in a 3D file. This is one of the reasons why Mentum Replicas can able you offer a perfect replica, i.e. a likeness that is entirely true to the original.

A method of scanning and measuring objects, photogrammetry uses trigonometric calculation to determine an object’s spatial situation or three-dimensional form using numerous photographs. The object is either photographed from multiple angles using the same camera or captured using multiple cameras at the same time.

Photogrammetry was developed as a geodetic method. Outside of scientific circles, it has recently gained prominence as a means of photographing individuals in order to generate a 3D-printed miniature likeness, with many German cities now having shops in which customers can have a full-body scan in order to get a mini-me statue of themselves.

At Mentum Replicas we, too, employ a photogrammetry rig to capture clients in three dimensions. Capable of photographing an entire individual in a thousandth of a second, such a rig is the ideal way to scan living, breathing beings incapable of remaining completely still; no other method offers the same accuracy. The accuracy of our captures is particularly high because our 360-degree photogrammetry rig is particularly complex, with more than 100 cameras precisely synchronised and pointed at the subject’s head, neck and torso. And because we use particularly high-resolution lenses, we get digital image data that allows us to create a perfect replica.

That data is subsequently translated into 3D images using a complex process and stored as .stl files.

For photogrammetry, Mentum Replicas uses nc3d:
www.nc3d.de/en/about-us/
en.wikipedia.org/wiki/Photogrammetry

The term plastic arts denotes art forms in which a realistic or abstract three-dimensional object is created, be it from clay, wax, glass, plaster, or some other formable material. Metals and plastics are also possible materials; here, modelling, moulding, casting or laser sintering can be used to form the object.

Point clouds are comprised of countless data points representing length, breadth and height coordinates. Three such points combine to form a two-dimensional triangle, which is, in turn, combined with others to form a three-dimensional model.

The lustrous stainless steel surfaces of our replicas are central to their captivating appeal. Although the special steel we use for the replicas ensures they have a fine lustre even fresh from the mill, they are still given a subsequent polish by Arnold AG’s skilled metalworkers in order to remove any small blemishes. Milling can leave fine lines (as a result of tool changes, for instance) that can be seen but not felt and these can be eliminated via polishing. Metal polishing is a technique that looks simple to the untrained eye but does, in fact, require a great deal of skill and care. The amount of polishing required depends on the replica’s size and level of detail, but hundreds of hours of manual polishing can go into one of our busts.

The creation of replicas is our core business, which is why the word forms part of the very name of our company and brand. A replica is a reproduction of an existing thing – be it a person, an animal or an object. A Mentum replica, meanwhile, is a reproduction that is perfectly faithful to the original thing. We are able to achieve such a high level of accuracy because we generally use 3D scanning to capture the subject, which allows us to work from highly accurate data. At Mentum Replicas, we don’t interpret reality, we create a true likeness of it.

Sculpture is a branch of the plastic arts and is always three-dimensional, though it can be either realistic or abstract. Commonly used materials include stone, wood, clay and metal. The two main sculptural techniques, as practice down the ages, are the removal of material via carving (i.e. cutting it away with a hard tool such as a chisel) and the addition of material via modelling.

The word sculpture derives from the Latin “sculptura” from the verb “sculpere” meaning carve.

One of the best known works of sculpture is the David statue by Italian sculptor Michelangelo (1475-1564). It can be seen in the Galleria dell’Accademia in Florence.
www.britannica.com/art/sculpture

The data set created via the 3D scan or by the digital sculptor has to be converted for input into a milling machine or 3D printer. This process is called surface reconstruction and is based on a polygonal mesh consisting of triangles. The resulting data is mostly stored as a .step or .igs file. Mentum Replicas uses Freeform GmbH for surface reconstructions.
www.freeform-gmbh.de
en.wikipedia.org/wiki/Polygon_mesh