In 3D computer graphics, 3D modeling is the process of developing a mathematical representation of any surface of an object (inanimate or living) in three dimensions via specialized software. The product is called a 3D model. Someone who works with 3D models may be referred to as a 3D artist or a 3D modeler. A 3D Model can also be displayed as a two-dimensional image through a process called 3D rendering or used in a computer simulation of physical phenomena. The 3D model can be physically created using 3D printing devices that form 2D layers of the model with three-dimensional material, one layer at a time. In terms of game development, 3D modeling is merely a stage in the entire development process.
An artist uses special software to manipulate points in virtual space (called vertices) to form a mesh: a collection of vertices that form an object. 3D Models may be created automatically or manually. The manual modeling process of preparing geometric data for 3D computer graphics is similar to plastic arts such as sculpting. 3D modeling software is a class of 3D computer graphics software used to produce 3D models. Individual programs of this class are called modeling applications.
3D Modeling In Action
3D modeling is an integral part of many creative careers. Engineers and architects use it to plan and design their work. Animators and game designers rely on 3D modeling to bring their ideas to life. And just about every Hollywood blockbuster uses 3D modeling for special effects, to cut costs, and to speed up production.
Learning 3D modeling can be quite a challenge. Many of the programs are complicated and good modeling principles are based on fundamental art skills. Those with experience in drawing and sculpture will have easier time learning to model. But really, anyone with time and patience can learn these skills.
How Does 3D Modeling Work?
An artist usually begins by generating some type of primitive like a cube, sphere, or plane. The primitive is just a starting shape to begin modeling. The artist will build upon this basic form and manipulate it using various modeling tools. For 3D modeling it’s almost always a good idea to start simple and work towards complexity.
3D modeling is a precise workflow often involving the painstaking placement of individual vertices to achieve the correct contours of the desired object.
The exterior of the mesh is composed of polygons which can be subdivided into smaller shapes to create more detail. These subdivisions are especially necessary if the 3D model is to be animated. Any joints that need to bend—such as a character’s knee or elbow—will need these additional polygons to ensure smooth motion.
Several tools exist to speed up the modeling process.
Once the model is complete the surface can be painted and textured.
Categories of 3D models:
Almost all 3D models can be divided into two categories:
- Solid – These models define the volume of the object they represent (like a rock). Solid models are mostly used for engineering and medical simulations, and are usually built with constructive solid geometry
- Shell or boundary – These models represent the surface, i.e. the boundary of the object, not its volume (like an infinitesimally thin eggshell). Almost all visual models used in games and film are shell models.
There are three popular ways to represent a model:
- Polygonal modeling– Points in 3D space, called vertices, are connected by line segments to form a polygon mesh. The vast majority of 3D models today are built as textured polygonal models, because they are flexible and because computers can render them so quickly. However, polygons are planar and can only approximate curved surfaces using many polygons.
- Curve modeling – Surfaces are defined by curves, which are influenced by weighted control points. The curve follows (but does not necessarily interpolate) the points. Increasing the weight for a point will pull the curve closer to that point. Curve types include nonuniform rational B-spline(NURBS), splines, patches, and geometric primitives
- Digital sculpting– Still a fairly new method of modeling, 3D sculpting has become very popular in the few years it has been around.
3D models are used for a variety of mediums including video games, movies, architecture, illustration and commercial advertising. They are also used in the medical industry to create interactive representations of anatomy. A wide number of 3D software are also used in constructing digital representation of mechanical models or parts before they are actually manufactured.
3D modeling is also used in the field of industrial design, wherein products are 3D modeled before representing them to the clients. In media and event industries, 3D modeling is used in stage and set design.