3D modeling capabilities allow you to create 3D images that are as realistic as the actual objects. These images are called 3D models because, just like a physical model, they can be rotated on the screen. You can display views from a 3D model, such as isometrics or perspectives, from any angle with a few simple steps.
3D modeling is usually a separate CADD module that has its own set of functions. Some manufacturers market 2D programs and 3D programs as separate packages while others combine them into a single program.
The 3D models fall into the following categories:
Wire-frame models
Surface models
Solid models
When you draw a model with lines and arcs, they are called wire-frame models. These models appear to be made of wires and everything in the background is visible. This does not create a very realistic effect.
Surface models are more realistic than wire-frame models. They are created by joining 3D surfaces rather than bare lines and arcs. A 3D surface is like a piece of paper that can have any dimension and can be placed at any angle to define a shape. Just like a paper model, you join surfaces to form a surface model. The views displayed from these models are quite realistic, because everything in the background can be hidden.
Solid models are considered solid inside and not hollow like a surface model. They appear to be the same as a surface model but have additional properties, such as weight, density and center of gravity, just like that of a physical object. These models are commonly used as prototypes to study engineering designs.
Example: You can draw a 3D model as a wire-frame, a surface model or a solid. To draw a 3D model of a cube as a wire-frame, you need to draw twelve lines by specifying 3D coordinates for each of its points. To draw it as a surface model, you need to draw all six surfaces of the cube. Although you see only three planes of the cube in front, it is essential to draw all the planes when drawing a 3D model. This ensures that a realistic view is displayed when it is rotated to display a view from any angle. When drawing a solid you can also specify its material.
Important Tip:
For general 3D drawings, wire frames and surface models are used. You start with a wire-frame model and then fill in spaces with 3D surfaces to make it more realistic.
3D modeling is usually a separate CADD module that has its own set of functions. Some manufacturers market 2D programs and 3D programs as separate packages while others combine them into a single program.
The 3D models fall into the following categories:
Wire-frame models
Surface models
Solid models
When you draw a model with lines and arcs, they are called wire-frame models. These models appear to be made of wires and everything in the background is visible. This does not create a very realistic effect.
Surface models are more realistic than wire-frame models. They are created by joining 3D surfaces rather than bare lines and arcs. A 3D surface is like a piece of paper that can have any dimension and can be placed at any angle to define a shape. Just like a paper model, you join surfaces to form a surface model. The views displayed from these models are quite realistic, because everything in the background can be hidden.
Solid models are considered solid inside and not hollow like a surface model. They appear to be the same as a surface model but have additional properties, such as weight, density and center of gravity, just like that of a physical object. These models are commonly used as prototypes to study engineering designs.
Example: You can draw a 3D model as a wire-frame, a surface model or a solid. To draw a 3D model of a cube as a wire-frame, you need to draw twelve lines by specifying 3D coordinates for each of its points. To draw it as a surface model, you need to draw all six surfaces of the cube. Although you see only three planes of the cube in front, it is essential to draw all the planes when drawing a 3D model. This ensures that a realistic view is displayed when it is rotated to display a view from any angle. When drawing a solid you can also specify its material.
Important Tip:
For general 3D drawings, wire frames and surface models are used. You start with a wire-frame model and then fill in spaces with 3D surfaces to make it more realistic.