Interactive graphic input system
AssigneeToshiba Kikai Kabushiki Kaisha
InventorsYukinori Kakazu, Noburo Minami, Yasuhiko Tamada, Hiroaki Uno
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Abstract
In the conventional CAD or CAM system, when a shape must be defined, it should use mathematical models which are formed by B-Reps or CSG method. B-Reps method is more complicated than CSG in data structure and in processing. This invention attempts to utilize merits of the CSG method, express component elements of a three-dimensional solid model in a hierarchical structure so that an element of a a higher order can relocate another element of a lower order on its coordinate system, and an interactive operation can be employed in defining. This method allows an operator to ascertain the progress of the works with his/her own eyes to greatly simplify the works of shape defining of solid models.
Claims14
An interactive graphic input method in a numerical control (NC) programming system which comprises a graphic display unit having means to display plural image frames, a keyboard for inputting alpha-numerals and codes, an input means such as a mouse unit which specifies an arbitrary position on the display screen of said graphic display unit with a cursor, a memory means for storing data, and a control and operation means for controlling and enabling the above respective units, said method comprising the steps of:
- preparing a primitive data file in which data of primitives are stored and which is provided in said memory means;
- preparing a shape data file in which data of shapes defined in structure are stored and which is provided in said memory means;
- decomposing an environmental shape into a hierarchical structure of constructive solid geometry (CSG) and specifying a component element from a bottom level to a top level of said hierarchical structure when said environmental shape which is selected from the group consisting of a workpiece shape, a machine tool shape, a fixture shape, and a tool shape is defined from said keyboard and input means;
- selecting one of plural primitives displayed on said graphic display unit by said input means in accordance with the data stored in said primitive data file and inputting dimensions of the selected primitive and an operation mode for setting a relation between the component elements from said keyboard and input means when said data of the primitives are inputted from said keyboard and input means and a name of the component element is inputted from said keyboard and input means;
- inputting a name of the component element, a marked name of a referred element and the operation mode from said keyboard and input means when data of a shape derived from a lower level of said hierarchical structure due to an operation, a name of the input component element and the operation mode are inputted from said keyboard and input means, and if a level of said hierarchical structure in the defined shapes stored in said shape data file is available;
- and
- repeating the above operations to a highest level of said hierarchical structure thereby to store the input results in said shape data file.
A method for defining shapes of a three dimensional solid model in computer aided design (CAD)/computer aided manufacturing (CAM) systems comprising the steps of:
- expressing component element of said three-dimensional solid model in a hierarchical structure of shape data consisting of parts, subparts, segments and elements;
- and
- defining a shape by a set of said component elements by using a constructive solid geometry (CSG) defining method;
- wherein a solid set operation between component elements at a same level is performed and a shape part at a next upper level is obtained, and said three-dimensional solid model is finally obtained by performing the above steps for each primitive from a lowest level to a highest level.
Dependencies are inferred from the claim text.