3D modeling is the “process of developing a mathematical representation of any three-dimensional surface of object… via specialized software.”¹ The process of 3D modeling and the cost of 3D modeling software are not easy to cope up with.² Dedicated programs or application components are used in creating 3D models, and sometimes scene descriptions languages are involved. At other times, modeling is merely a part of a creation process.¹ And the “most powerful tool” is our imagination.⁵ 3D models are seen everywhere: in movies, in product designs, in advertisements, etc, but this does not mean that they are easily created.² Creating 3D models is not as easy as creating 2D ones.⁵ 3D models are “objects that are constructed on three planes.”² They are composed of points connected by geometric entities. Examples of geometric entities are triangles, lines, curved surfaces, etc. There are two ways to create models: automatic and manual (which is similar to sculpting). They are made by hand, algorithmically, or scanned.¹

3D computer graphics are “programs used to create 3D computer-generated imagery.” Some of these programs are specifically developed for certain objects only, such as chemical compounds or internal organs, and for certain processes only, such as skeletal animation.^1,3 Users of 3D computer graphics interact with each other in forums to share their ideas. They share some tips and tricks on how to use graphics software. For example, three or more designers can collaborate on a project. A sub-forum is a “great place to share your experiences and do your Q&A with other users.” Groups are “starting points for discussions and collaborations.”⁵

Tessellation is the “process of transforming representations of objects, such as the middle point coordinate of a sphere and a point on its circumference into a polygon representation of a sphere.” This is used in breaking down primitives (spheres, cones, etc) to meshes (interconnected triangles). Lighting is an “important aspect of scene setup” and a “significant contributing factor to the resulting aesthetic and visual quality of the finished work.”¹

The following are the three basic phases of the process of creating 3D graphics:²

1. 3D modeling
2. 3D animation
3. 3D rendering

Majority of solid models belongs to one of the following categories:¹

• Solid
• Shell/Boundary

Solid models are realistic models that are hard to build. They have uses in non-visual simulations and in visual applications. Examples of non-visual simulations are medical and engineering simulations. Examples of visual applications are ray tracing and constructive solid geometry. Compared to solid models, shell/boundary models are easier to deal with. The exteriors of these objects define their boundaries. For instance, the focus of a shell/boundary model is its surface and its boundaries but not its volume.¹

The following are digital approximations that are required to be used for nonfinite surfaces:¹

• Polygonal meshes
• Point-based representations
• Level sets

Polygonal meshes are the “most common representation.” However, point-based representations are now gaining popularity. Level sets are a “useful representation for deforming surfaces which undergo many topological changes.” An example of these surfaces is fluids.¹

The following are popular ways to represent models:¹

• Polygonal modeling
• NURBS (Non-Uniform Rational B-Spline) modeling
• Splines and patches modeling
• Primitives modeling
• Sculpt modeling

The flexibility and ease of rendering have caused users to create a lot of models using polygonal modeling. NURBS modeling and splines and patches modeling are similar with each other in terms of their dependence to curved lines in defining visible surfaces. But if it is based on flexibility and ease of use, splines and patches modeling falls between the first two: polygonal modeling and NURBS modeling. Primitives modeling is more suitable to use in technical applications that does not have much organic shapes. It provides the following benefits: quick and easy construction, mathematically defined and absolutely precise forms, and simpler definition language. Geometric primitives serve as the building block of its models. Examples of these primitives are balls, cylinders, cones, etc.¹

There are two types of sculpt modeling:¹

• Displacement
• Volumetric

Both of them allow a very artistic exploration of the model. However, the former is more popular than the latter.¹

Some modeling techniques are the following:¹

• Constructive solid geometry
• Implicit surfaces
• Subdivision surfaces

3D modeling has advantages over 2D methods. These are the following:¹

• Flexibility
• Ease of rendering
• Accurate photorealism

Flexibility is the “ability to change angles or animate images with quicker rendering of the changes.” Ease of rendering results from an automatic calculation and rendering, and mental visualization and estimation. Accurate photorealism is marked by minimized human errors in applying visual effects. However, sometimes it is difficult to achieve certain photorealistic effect. This is one disadvantage of 3D modeling.¹

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¹“3D modeling.” Wikipedia. 2010. Wikimedia Foundation. 16 Aug 2010 <http://en.wikipedia.org/wiki/3D_modeling>.
²Kay. “25 (Free) 3D Modeling Applications You Should Not Miss.” Online posting. 14 Aug 2010. Hongkiat.com. 16 Aug 2010 <http://www.hongkiat.com/blog/25-free-3d-modelling-applications-you-should-not-miss/>.
³“3D computer graphics software.” Wikipedia. 2010. Wikimedia Foundation. 16 Aug 2010 <http://en.wikipedia.org/wiki/3D_computer_graphics_software>.
⁴“Free Noncommercial 3D ‘Three-Dimensional’ Model Library.” Artist 3D. 13 July 2010. 23 Aug 2010 <http://artist-3d.com/>.
⁵Saikat Basu. “Easily Learn 3D Modeling with 3DVIA Shape.” Online posting. 15 June 2010. MakeUseOf. 23 Aug 2010 <http://www.makeuseof.com/tag/3d-modeling-skills-easy-3dvia-shape/>.

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