ENG 004 Lecture 8, Oct 23, 2012



3D primitives and model types

Constructive Solid Geometric Modeling

3D Primitives

3D Primitives

3D Primitives

3D Primitives

3D Primitives

Ruled Surfaces

Undeveloped Surface

3D Modeling: Node Model

3D Modeling: Surface Model

3D Modeling: Solid Model

Sketch Planes

World coordinate planes (WCP) are associated with the world coordinate system (WCS)

Sketch (Work) Plane

Coincident or relative to a WCP

Can be a plane or projected plane that already is in the model

Sketch Plane Creation

Solid Model Boolean Operations

Constructive solid geometric modeling (CSG) uses Boolean operations and constructive operations to create a solid model.

Boolean operations

In order for Boolean operations to be logical, the features must be either overlapping or touching.

Boolean Operations: Union

Boolean Operations: Intersection

Boolean Operations: Difference

Boolean Operations: Difference

Solid Model Constructive Operations

  • Define a work plane
  • Define a closed profile (sketch) using 2D primitives
  • Infinite, unbounded 2D plane placed and oriented anywhere in the 3D domain of the model
  • A local coordinate system (LCS) or user coordinate system (UCS) is associated with the World Coordinate System (WCS)
  • A 2D profile is defined






Constructive Operations

Extrude (linear sweep)

Define length and direction of the extrusion. The direction cannot be parallel to the work plane.


Define the axis and amount of rotation

Sweep (path based sweep)

Define a space curve along which the sweep occurs


Define a space curve and intermediate profiles along the curve.

Feature Planning

Sketch Constraint Quiz

pg 117 for constraint types, groups of 3-5, all names on one paper