A wire frame model is a visual presentation of a three dimension

Dimension

In physics and mathematics, the dimension of a space or object is informally defined as the minimum number of coordinates needed to specify any point within it. Thus a line has a dimension of one because only one coordinate is needed to specify a point on it...

al or physical object used in 3D computer graphics

3D computer graphics

3D computer graphics are graphics that use a three-dimensional representation of geometric data that is stored in the computer for the purposes of performing calculations and rendering 2D images...

. It is created by specifying each edge of the physical object where two mathematically continuous smooth surfaces meet, or by connecting an object's constituent vertices

Vertex (computer graphics)

A vertex in computer graphics is a data structure that describes a point in 2D or 3D space. Display objects are composed of arrays of flat surfaces and vertices define the location and other attributes of the corners of the surfaces.-Application to object models:In computer graphics, objects are...

 using straight lines or curves. The object is projected onto the computer screen by drawing lines at the location of each edge.The term wireframe comes from designers using metal wire to represent the 3 dimensional shape of solid objects.3D wireframe allows to construct and manipulate solids and solid surfaces.3D solid modeling technique efficiently draws high quality representation of solids than the conventional line drawing.

Using a wire frame model allows visualization of the underlying design structure of a 3D model. Traditional 2-dimensional views and drawings can be created by appropriate rotation of the object and selection of hidden line removal

Hidden line removal

Hidden line removal is an extension of wireframe model rendering where lines covered by surfaces are not drawn.This is not the same as hidden face removal since this involves depth and occlusion while the other involves normals....

 via cutting planes.

Since wireframe renderings are relatively simple and fast to calculate, they are often used in cases where a high screen frame rate is needed (for instance, when working with a particularly complex 3D model, or in real-time

Real-time computing

In computer science, real-time computing , or reactive computing, is the study of hardware and software systems that are subject to a "real-time constraint"— e.g. operational deadlines from event to system response. Real-time programs must guarantee response within strict time constraints...

 systems that model exterior phenomena). When greater graphical detail is desired, surface textures can be added automatically after completion of the initial rendering of the wireframe. This allows the designer to quickly review chansolids or rotate the object to new desired views without long delays associated with more realistic rendering

Rendering (computer graphics)

Rendering is the process of generating an image from a model , by means of computer programs. A scene file contains objects in a strictly defined language or data structure; it would contain geometry, viewpoint, texture, lighting, and shading information as a description of the virtual scene...

.

The wire frame format is also well suited and widely used in programming tool paths for DNC (Direct Numerical Control) machine tools.

Wire frame models were used extensively in video games to represent 3D objects during the 1980s and early 1990s when properly filled 3D objects would have been too complex to calculate and draw with the computers of the time. Wireframe models are also used as the input for CAM(computer-aided manufacturing

Computer-aided manufacturing

Computer-aided manufacturing is the use of computer software to control machine tools and related machinery in the manufacturing of workpieces. This is not the only definition for CAM, but it is the most common; CAM may also refer to the use of a computer to assist in all operations of a...

).

There are mainly three types of 3D CAD models. Wireframe is one of them and it is most abstract and least realistic. Other types of 3D CAD models are surface and solid. This method of modelling consists only lines,points and curves defining the edges of a object.

Introduction

Wireframing is one of the method of geometric modelling system. A wireframe model represents shape of solid object by its characteristics lins and points.There are two types of wireframe modelling.1)Pro's and 2)Con's.In Pro's user gives a simple input to create a shape.It is useful in developing system.While in Con's wireframe model,it does not include information about inside and outside boundary surfaces.Now-a-days in mechanical design wireframe models are used in defining complex solid objects.The designer makes wireframe model of a solid object first and then CAD operator reconstructs the object including detailed analysis.In this way a solid object is created indirectly by using wireframe technique.This technique has some advantage as follow-1)Generally the 3 dimensional solid objects are complex, wireframe model can be viewed in 1 dimension so this compactness helps designer.2)The solid object can be modified furthur.The designer can ignore the geometry inside surface while in solid modelling designer has to give consistent geometry for all details.3)Wireframe models require less space and also very few resources from CPU.

Simple example of wireframe model

It is one of the oldest method of representing objects.It consists of details, given in form of two tables :-1)vertex table and 2)edge table.Vertex table consists of co ordinate values of each vertex with reference to origin.While edge table consists of vertices in which the given edge terminates.But it does not contain face information.

Vertex	X	Y	Z
1	1	1	>-	2	1	-1	1
3	-1	-1	1
4	-1	1	1
5	1	1	-1
6	1	-1	-1
7	-1	-1	-1
8	-1	1	-1

Edge	Start Vertex	End Vertex
1	1	>-	2	2	3
3	3	4
4	4	1
5	5	6
6	6	7
7	7	8
8	8	5
9	1	5
10	2	6
11	3	7
12	4	8

Methods for creating 3D wireframe

1. Extrusion
   Extrusion
   Extrusion is a process used to create objects of a fixed cross-sectional profile. A material is pushed or drawn through a die of the desired cross-section...
   
   : It is technique for creating a 3D wireframe model by copying a 2D profile and extending it to a depth defined the operator. The result is a 3D wireframe of the profile.
2. Rotation: Rotation produces wireframe models by rotating a cross section or profile of the part about an axis.It is similar to extrusion except it is swept about an axis.
3. Extrusion with scale: Extrusion with scale technique comprises of defining the depth along with the facility of enlarging scale uniformly.
4. Using primitive shapes to build models.

Use of wireframe model

1. Viewing the model from any desired point-This can be obtained by changing line of sight.
2. To produce standard orthographic and auxillary views:-Orthographic views are created by changing the line of sight so that it is perpendicular to the front,top and profile faces of the model for creating front view(elevation),top view(plan) and side view respectively.After the orthographic views are created,they must be edited to remove extraneous lines and to add hidden and centre lines so the drawing conforms with the standards.
3. To produce exploded and perspective view more easily.
4. To analyse distances within the structure and checking tolerances and interference.
5. To decrease number of prototypes required.
6. Editing the model:-Some CAD systems can automatically remove hidden lines using a command called hide.

Why wireframe models are ambiguous

Let us take an example of a cube as shown in the figure.it has 16 vertices and 32 edges.
The inner cube denotes the hole.But we cannot guess whether direction of opening is front,back,sideways or any other direction.Hence this model of cube does not allow free interpretation.Hence as the wire frame models are ambiguous their uses are limited.
However wireframe models are well known due to their efficiency f working.Wireframe models can provide feeling of final result without waiting for hours and days of designs.

See also

• Animation
  Animation
  Animation is the rapid display of a sequence of images of 2-D or 3-D artwork or model positions in order to create an illusion of movement. The effect is an optical illusion of motion due to the phenomenon of persistence of vision, and can be created and demonstrated in several ways...
  
  
• Computer animation
  Computer animation
  Computer animation is the process used for generating animated images by using computer graphics. The more general term computer generated imagery encompasses both static scenes and dynamic images, while computer animation only refers to moving images....
  
  
• Computer-generated imagery
  Computer-generated imagery
  Computer-generated imagery is the application of the field of computer graphics or, more specifically, 3D computer graphics to special effects in art, video games, films, television programs, commercials, simulators and simulation generally, and printed media...
  
   (CGI)
• 3D computer graphics
  3D computer graphics
  3D computer graphics are graphics that use a three-dimensional representation of geometric data that is stored in the computer for the purposes of performing calculations and rendering 2D images...
  
  
• Polygon mesh
  Polygon mesh
  A polygon mesh or unstructured grid is a collection of vertices, edges and faces that defines the shape of a polyhedral object in 3D computer graphics and solid modeling...
  
  
• Vector graphics
  Vector graphics
  Vector graphics is the use of geometrical primitives such as points, lines, curves, and shapes or polygon, which are all based on mathematical expressions, to represent images in computer graphics...
  
  
• Mockup
  Mockup
  In manufacturing and design, a mockup, or mock-up, is a scale or full-size model of a design or device, used for teaching, demonstration, design evaluation, promotion, and other purposes...
  
  

External links

1.* "simple example of wireframe model"

2.*"creating wireframe model"

3.*"building wireframe model"

4.*"9 real wireframe models"

5.*"Applications of wireframe model"

6.*"Examples of wireframe model"

7.*"web wire frame modelling software"

8.*"wireframe model tutorials"