A wireframe model is an edge or skeletal representation of a real-world 3D object using lines and curves.
Wireframe models consist only of points, lines, and curves that describe the edges of the object. Because each object that makes up a wireframe model must be independently drawn and positioned, this type of modeling can be the most time-consuming.
You can use a wireframe model to
- View the model from any vantage point
- Generate standard orthographic and auxiliary views automatically
- Analyze spatial relationships, including the shortest distance between corners and edges, and checking for interferences
- Reduce the number of prototypes required
- Generate exploded views easily
- Generate perspective views easily (not available in AutoCAD LT)
The ISOLINES system variable controls the number of tessellation lines used to visualize curved portions of the wireframe. The FACETRES system variable adjusts the smoothness of shaded and hidden-line objects.
Methods for Creating Wireframe Models
You can create wireframe models by positioning any 2D planar object anywhere in 3D space, using the following methods:
- Enter 3D coordinates that define the X, Y, and Z location of the object.
- Set the default work plane (the XY plane of the UCS) on which to draw the object.
- Move or copy the object to its proper 3D location after you create it.
- Use the XEDGES command to create wireframe geometry from regions, 3D solids, surfaces, and meshes. XEDGES extracts all the edges on the selected objects or subobjects. The extracted edges form a duplicate wireframe composed of 2D objects such as lines, circles, and 3D polylines. (This feature is not available in AutoCAD LT.)
Wireframe modeling is a skill that requires practice and experience. The best way to learn how to create wireframe models is to begin with simple models before attempting models that are more complex.
Tips for Working with Wireframe Models
Creating 3D wireframe models can be more difficult and time-consuming than creating their 2D views. Here are some tips that will help you work more effectively:
- Plan and organize your model so that you can turn off layers to reduce the visual complexity of the model. Color can help you differentiate between objects in various views.
- Create construction geometry to define the basic envelope of the model.
- Use multiple views, especially isometric views, to make visualizing the model and selecting objects easier.
- Become adept at manipulating the UCS in 3D. The XY plane of the current UCS operates as a work plane to orient planar objects such as circles and arcs. The UCS also determines the plane of operation for trimming and extending, offsetting, and rotating objects.
- Use object snaps and grid snap carefully to ensure the precision of your model.
- Use coordinate filters to drop perpendiculars and easily locate points in 3D based on the location of points on other objects.
