Mumbai University > Mechanical Engineering > Sem 7 > CAD/CAM/CAE

Marks: 10 M

Year: May 2013

Wire frame modelling

Wire frame modelling is an edge or skeletal representation of a real-world 3D object using lines and curves.

Merits:

1. Simple to construct for 2D and simple and symmetric 3D objects
2. Designer needs little training
3. System needs little memory
4. Take less manipulation time
5. Retrieving and editing can be done easy
6. Consumes less time
7. Best suitable for manipulations as orthographic isometric and perspective views.

Demerits:

1. Image causes confusion
2. Cannot get required information from this model
3. Hidden line removal features not available
4. Not possible for volume and mass calculation, NC programming cross sectioning etc
5. Not suitable to represent complex solids

Surface modelling

Surface models define the surface features, as well as the edges, of objects. Different types of spline curves are used to create surface patches with different modelling characteristics.

Merits:

1. It is less ambiguous.
2. Complex surfaces can be easily identified.
3. It removes hidden line and adds realism.

Demerits:

1. Difficult to construct.
2. Difficult to calculate mass property.
3. More time is required for creation.
4. Requires high storage space as compared to wire frame modelling.
5. Also requires more time for manipulation.

Solid Modelling Solid Modelling is a modelling that provides a complete representation of an object than a wire frame modelling and surface modelling. In this model, the appearance of an object is displayed in solid design.

Merits:

1. Complete modelling.
2. Unambiguous.
3. Best suitable for calculating mass properties.
4. Very much suitable for automated applications.
5. Fast creation.
6. Gives huge information.

Demerits:

1. Requires large memory.
2. Slow manipulation.
3. Some manipulations can be complex and require tedious procedure.