List of: Scheme Data Types
Subjects: Entity, Model Object
Contents: Scheme Support

Description: An entity is a top-level object from which all other objects representing permanent objects in ACIS, such as geometric, topological, attribute, and transform objects, are derived. It does not represent any specific object within the modeler. Instead, it represents common data and functionality that must be contained in all classes that represent permanent objects within the modeler. entity objects are saved and restored as part of the model.

An entity may also contain pointers from objects to system-defined and user-defined attributes. Not all objects use attribute pointers, but automatic creation and deletion of attributes for any object is supported.

A deleted entity is an entity that has been deleted but is still referenced by some other scheme-object or procedure. Deleted entities cannot be directly used. However, if the state of the model is rolled back past the point of deletion, the entity returns and can be used again.

Derivation: entity : scheme-object

C++ Type: ENTITY

External Rep: #[entity %d %d]

where the first integer is the entity ID,

and the second integer is the part ID.

#[(deleted) entity %d]

where the integer is the entity ID.

Example: ; entity (data type)

; Create and inquire an entity object.

(define my_torus (solid:torus

(position -10 -10 -10) 7 3))

;; my_torus

(entity? my_torus)

;; #t