Method for generating representations of 3-dimensional objects and system performing this method

Claim 2

Method for generating representations of 3- dimensional objects, especially models of mechanical parts, in a computer aided design system, said system comprising a processor connected with at least one user input interface and one user output interface via appropriate registers, characterized in that a) in a 2D mode, the processor (10) only accepts and processes commands relating to the 2D geometry of an object in a given plane whilst having access to a 2D read/write memory (16), said 2D mode being performed under control of the instructions contained in a 2D-instruction memory (15, 15a); b) whenever a command is entered relating to the 3D geometry of said object while the processor (10) operates in said 2D mode, control is transferred to a transformation instruction memory (21, 22), and the processor (10) will then execute the instructions contained in this memory (21) which implement the following steps: b1) said 2D geometry is transformed into a corresponding 3D geometry; and b2) control is then transferred to a 3D-instruction memory (24), and the processor (10) will then execute the instructions contained in this memory (24) to process and/or store said 3D geometry whilst having access to a 3D-read/write memory (27).

Claim 3

Method according to claim 1, characterized in that the geometry of said object is checked with respect to topological errors any time the 2D geometry is transformed into a 3D geometry, preferably under control of said transformation instruction memory (21, 22).

Claim 4

Method according to claim 1 or claim 2, characterized in that under control of said 3D-instruction memory (24), the created object may be modified in its characteristics related to its 3-dimensional representation, preferably by adding/subtracting predefined geometric objects or performing Bolean operations.

Claim 5

Method according to at least one of the preceding claims in which the user can select a multiplicity of views on said user output interface, characterized in that all of these views are updated any time control is transferred to said 3D-instruction memory (24) or a special command is entered by the user.

Claim 6

Computer aided design system comprising: a) at least one user input interface, preferably a keyboard and/or a graphics tablet; b) a digital processor connected to said user input interface via an input register; c) at least one user output interface, preferably a screen with graphics capabilities, said user input interface being connected to said digital processor via an output register; characterized in that said digital processor is connected with d) a 2D-instruction memory (15, 15a) containing only instructions for the processing and/or controlling of 2-dimensional representations of 3- dimensional objects, said processor (10) - when executing these instructions - having access to a 2D-read/write memory (16) which contains the geometrical specifications and related data of said two-dimensional representations of said 3-dimensional objects; e) a 3D-instruction memory (24) containing only instructions for the processing and/or controlling of 3-dimensional representations of three-dimensional objects, said processor (10) - when executing these instructions - having access to a 3D-read/write memory (27) which contains the geometrical specifications and related data of said 3-dimensional representations of said 3-dimensional objects; f) a transformation instruction memory (21, 22), said memory (21, 22) containing instructions for transforming 2-dimensional representations of 3-dimensional objects into 3-dimensional representations of the same, and vice versa.

Claim 7

Computer aided design system comprising: a) at least one user input interface, preferably a keyboard and/or a graphics tablet; b) a digital processor connected to said user input interface via an input register; c) at least one user output interface, preferably a screen with graphics capabilities, said user input interface being connected to said digital processor via an output register; characterized in that said digital processor is connected with d) a 2D-instruction memory (15, 15a) containing only instructions for the processing and/or controlling of 2-dimensional representations of 3- dimensional objects, said processor (10) - when executing these instructions - having access to a 2D-read/write memory (16) which contains the geometrical specifications and related data of said two-dimensional representations of said 3-dimensional objects; e) a 3D-instruction memory (24) containing only instructions for the processing and/or controlling of 3-dimensional representations of three-dimensional objects, said processor (10) - when executing these instructions - having access to a 3D-read/write memory (27) which contains the geometrical specifications and related data of said 3-dimensional representations of said 3-dimensional objects; f) a transformation instruction memory (21, 22), said memory (21, 22) containing instructions for transforming 2-dimensional representations of 3-dimensional objects into 3-dimensional representations of the same, and vice versa.

Claim 8

Computer aided design system according to claim 5, characterized in that said transformation instruction memory (21) contains instructions for a two-dimensional topology check (22).

Claim 9

Computer aided design system according to claim 5 or claim 6, characterized in that said transformation instruction memory (21, 22) comprises a profile processor (33) which transforms a 2D geometry into a 3D geometry, and a rendering processor (32) which receives 3D geometric information, converts it in 2D views and stores it in said 2D data memory (16).

Claim 10

Computer aided design system according to at least one of claims 5 to 7, characterized in that said 2D data memory (16) is divided into at least two parts (16a, 16b), one of these parts (16a) containing only information about the 2D view the user is editing, while the other (16b) contains information about views to which the user has no write access.