A technology such as 3D printing is now actively used to create a wide variety of objects, this is far from entertainment, but a full-fledged and useful weapon that makes our life easier.
Three-dimensional modeling and printing of 3D models have found their application in many sectors of human activity and are in great demand today.
Like any field of activity, 3D printing technologies have their own terminology that is not always clear to an ordinary person or someone who is just trying to figure out a new field for him. For example, mesh 3D printing. First of all, we will understand the meaning of the term “mesh”.
With this word, experts call all the polygons, edges and vertices that make up this or that 3D object. That is, in other words, this is a kind of volumetric geometric construction of the subject.
Polygon modeling for 3D printing
There are several types of three-dimensional modeling: wireframe, solid-state, surface, generative and polygonal. Volumetric visualization using polygons is the very first kind of 3D modeling. Polygon modeling 3D max has its own nuances and difficulties, however, this method is still very popular in the field of 3D technology.
What is polygonal modeling
Polygonal modeling is low-level modeling that allows visualizing an object using a polygonal mesh.
Polygonal meshes consist of the following sub-objects:
- vertex – the connection point of the ribs; there can be any number of them;
- edges – lines protruding by the boundaries of faces;
- faces or polygons — grid cells, sections of a plane that are most often triangular or quadrangular. A polygonal mesh can consist of a huge number of identical cells.
To create a three-dimensional model of an object, one must work with subobjects. One can change their scale and shape, rotate, combine and divide, as well as apply other operations that allow special computer programs.
Polygonal modeling is performed in the following programs:
- 3Ds Max;
Polygonal meshes are a collection of polygons from which contours are formed, the shell of the future object. It seems that it is not difficult to work with them, they have clearly defined external and internal areas, no additional parameters and calculations need to be done.
However, this method requires patience and perseverance, because to create even the simplest three-dimensional model, it is needed to make thousands of mouse clicks. The smallest mistake can reduce all the work not to “no” since it is very difficult to remake the finished object.
Methods for constructing polygonal models
There are three main techniques for creating polygonal models, which are most often used in a combined version but can be used in pure form.
With the help of primitives – when ready-made geometric shapes are taken as the basis (for example, a cube or cylinder), then the desired model is constructed by stretching subobjects, dividing existing faces.
Pulling new faces from the source polygon when each subobject appears from the previous one.
Manually, without source codes and primitives, when all subobjects are drawn, but not extended.
Polygonal modeling provides three main methods for constructing visualization objects.
Modeling with vertices – manipulations with vertices, their movement, removal, etc. are performed.
Modeling with edges – to give the desired shape to the object, the position of the edges, their size, changes.
Modeling with polygons – faces are used for more complex operations, for example, making the shapes convex or, on the contrary, sharpening, smoothing or indenting the surface, here we work with planes.
Polygonal modeling is primarily designed to create three-dimensional models of objects with precise shapes and clear contours. Objects are made up of polygons – tiny faces that have a shape and color. This method is today most often used in industrial design.
Mesh 3D printing
Creating 3D models and printing them on a 3D printer is a rather complicated process that requires professional knowledge and experience.
If you have a ready-made three-dimensional model of the object or you plan to create it, then before you start printing it on a 3D printer, you will need to first prepare the model for printing. The better the 3D model is prepared, the better the finished result will be.
How to prepare a 3D model for 3D printing?
Export the 3D model to the desired format – most often for printing on a 3D printer, files of the STL and WRL format are accepted – for the development of colors when printing with multicolor plaster, a .jpg or .png file with a texture must be attached to the WRL file.
Make sure your model meets the minimum and maximum dimensions for 3D printing of the selected material. 3D printers for printing from one or another material have different dimensional restrictions – you can get acquainted with the acceptable sizes on the pages of materials for 3D printing.
In the process of creating a model, check the individual modeling requirements for 3D printing from a particular material: check wall thicknesses, parameters of convex or engraved parts, etc.
Make sure your 3D model is not turned inside out. To do this, all normals should be oriented outward – this allows the 3D printer to determine the internal and external surface of the model.
Make sure that your 3D model does not have holes in the polygon mesh. Remember the basic modeling requirement for 3D printing – the model must be “waterproof”, i.e. have a closed polygon mesh.
The geometry of the future product should be tight, and the normals should not be turned out, otherwise, the printer will “understand” them as holes. You must check the mesh for any extra internal geometry.
The protruding parts of the mesh.
Too thin protruding parts of the mesh can break off during the post-press processing of the model or during transportation. For example, when printing a character, special attention should be paid to his wrists, shoulders, neck, and ankles. In this case, it is necessary to think about the character’s pose, making it more stable.