In these days 3D modeling reaches its mainstream popularity. It is wildly used in both gaming and movie environment as well as in science and engineering sectors.
So what is 3D modeling? In simple phrases, 3D modeling is a creation of fully rendering three-dimensional objects or scenes. The product of 3D modeling is called a 3D model or a 3D object.
Fundamentally, 3D object is a number of points in space connected by complex geometric entities (for example triangles, curved surfaces, lines, etc.). They can be created by hand or automatically using different 3D software programs (3ds Max, AutoCAD, Autodesk Maya, etc.). 3D designers and animators are in high demand today as they create the core essential of 3D world – 3D models.
Where to use 3D models?
- Computer animated films industry uses 3D models for creation of animated characters and objects.
- 3D models are the basic objects in video games environment.
- Medical industry often uses detailed 3D models of human organs.
- 3D models of chemical compounds are wildly used in the science sector.
- Architects and real estate builders often use 3D to visualize architectural objects.
- Engineers use 3D models for presentation of new devices, vehicles, etc.
As mentioned above, 3D modeling is on the crest of the wave and the field of its application will increase year after year.
Two basic categories of 3D models
- Solid 3D models are more realistic and complex to create and are often used for simulation of medical and engineering objects as they represent the volume of an object or a surface.
- As to shell models, this category is more popular and is wildly used in gaming and movie environment. Unlike solid models, 3D shell models represent the boundary of an object, not its volume. They are also called boundary models.
3D models also differ in the way they are created and manipulated. Let’s have a look at two major types of 3D models: NURBS and Polygons.
Or a non-uniform rational basic spline modeling creates 3D models for surfaces and curves representation. This type of modeling has a lot of advantages such as:
- great flexibility;
- high precision.
This allows to create curves that we can often use in computer-aided design, architecture and engineering (for example, in automotive design).
Specific aspects of a NURB curve are the knot vectors, a set of control points and the order of curves. These control points are organized in a certain order creating a curve which can be seen in 3D model. Weight is applied to certain control points on a curve and these weighted points influence the direction of a curve. The knot vector is a set of parameters that define how the control points affect the curve.
The curves can be quickly and efficiently assessed with help of specific algorithm.
This type of 3D models is the most common form of 3D models; it uses polygons to create a shell of a 3D model. For this reason it is often called Shall modeling. Polygonal or shall 3D models are used in creation of animated movies and in video game industry.
Using polygonal modeling you can create simple shapes, such as triangles, quads and cube. These simple shapes are called object primitives and they all can form the basis of a complex 3D polygonal model.
The basic object of polygonal 3D model is called vertex - the coordination points in three-dimensional space. Two connected vertices create an edge; three vertices, connected by three edges, create a triangle and so on. Triangle is the simplest polygonal 3D model and you can further create more complex model using triangles. Triangle and quads are the most often used shapes in polygonal 3D modeling. Each polygon creates an element which is called a face.
As we noted, each polygonal 3D model consists of vertices, edges and faces. Let’s consider these components in details.
- Vertices define the structure of faces. When you move the vertices (push or pull) or edit them (you can edit the x, y, and z-axes), this affects the shape of the faces. This is the most common technique in 3D software programs like Maya and 3d Max and it helps to create the final shape of a polygonal 3D model. Independent vertices can be also used to create faces, but they will be invisible when rendering a model.
- Edges are points on 3D model surface where two polygonal faces meet.
- Faces: one of the main differences between NURB modeling and polygonal modeling is that each polygon shape creates a face. So the surface of a complex 3D model consists of hundreds of geometric faces.
Professional 3D animators try to create 3D models with many details and of high resolution (or polygon density) to make the final model look smooth and natural when rendering.
There are two more important aspects of 3D modeling to be considered.
Textures and Shaders
Every detail matters in a 3D world. Proper adjusted levels of light and color as well as realistic surface of a 3D model add vividness to the object and improve its visual appearance. To make a 3D model look realistic it is recommended to set appropriate parameters in Shader application and to overlay suitable texture.
- Shaders are wildly used to produce lightning and shades in 3D modeling. It is a set of parameters applied to a 3D model allowing to adjust light, opacity, reflectivity, shading and a lot of other parameters. Shaders are often applications available in a standard 3D modeling package.
- Textures. Texturing or mapping is another method of adding realistic look to a 3D object. You can overlay a two-dimensional image or even a real photo of a texture on the surface of your 3D model. This process is known as texture mapping and allows to achieve a high level of details of an object.
There is a great number of techniques and aspects of 3D modeling we should use to reach the desired result. Proper texturing and shading make a great contribution to the realistic effect of a modeled object.
3D modeling is a huge field to explore and there are definitely a vast number of aspects we consider to create perfect 3D models.