Entry Manipulation
Manipulation of the Model
Manipulation -> Modification of drawings, erase unwanted parts, move some geometry around the drawing, or to copy some repeated detail.
The facilities that typically provided for manipulation of the model: Four groups of functions:
Those that apply the transformations of translation, rotation and scaling to elements of the model (moving the geometry, copying the geometry to create one or more duplicate sets of entities in the data structure. Those that allow the user to make changes to individual geometric elements to trim or extend them to their intersections with other elements. Functions for the temporary or permanent deletion of entities from the model. Miscellaneous functions that, for example, allow entities to be grouped together.
Object transformations
When the entities of a CAD model are manipulated by moving them around, or by taking one or more copies at different locations and orientations, we image the coordinate system to be stationary, and the object to move.
Trim and extend operations
Trimming involves removal of a part of entity bounded by one or more bounding intersections. Extending involves the extension of an entity to one or more boundaries.
Other Functions
Like The deletion of entities from the model (blanking or hiding for temporary deletion). The collection of a number of entities together (group or block) and the modification of entity features, such as their color or line style.
