Computer graphics processing and selective visual display system – Computer graphics processing
Reexamination Certificate
1997-10-03
2001-04-10
Powell, Mark R. (Department: 2779)
Computer graphics processing and selective visual display system
Computer graphics processing
Reexamination Certificate
active
06215493
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a three-dimensional CAD system and method of converting two-dimensional drawings to three-dimensional drawings. With the present invention, three-dimensional CAD drawings (solid views) of various shapes can be easily made based on two-dimensional CAD data recorded as a two-dimensional CAD drawing.
BACKGROUND OF THE INVENTION
Three-dimensional CAD drawings are solid views which have several advantages over two-dimensional CAD drawings in that contours of product shapes can be recognized at a glance and product shapes can be easily understood.
Conventionally, the following labor-intensive work has been performed out to convert two-dimensional CAD drawings drawn isometrically to three-dimensional CAD drawings.
(1) Print a two-dimensional CAD drawing with dimensions that has been previously entered.
(2) Pick-up the dimensions from the printed two-dimensional CAD drawing by hand.
(3) Ridges and peaks relating to the dimensions that have been picked up are then inputted by hand onto three-dimensional axes of a grid drawn onto a monitor connected to the CAD system. Spline interpolation is then carried out with respect to a curved plane.
Three-dimensional CAD data corresponding to the two-dimensional CAD drawings is then obtained by drawing three-dimensional CAD drawings (solids) on the monitor using the aforementioned procedure.
In another conventional method, three-dimensional shapes of products are completed by inputting two-dimensional CAD drawings to planes in three dimensions and performing a transition in the third dimension direction.
However, in this conventional method of converting to a three-dimensional CAD drawing, the dimensions are read-in by inspection and a method of working where inputting is carried out by designating ridges and peaks corresponding to the read-in dimensions on a screen using a pointing device (coordinate input device such as a mouse etc.) is performed. Therefore, even in the case of a simple part such as a part for a motorcycle, the time required for inputting this information to construct a three-dimensional CAD drawing from a two dimensional CAD drawing is substantial. Furthermore, it is necessary to consider the likelihood of input mistakes and their effect on the three-dimensional drawing. Also, there are a large number of processes to make such a three-dimensional CAD drawing. The practical result is that three-dimensional CAD drawings can only be obtained for a limited number of products.
Therefore, in the related art, a three-dimensional figure data generating method has been proposed (for example, refer to Japanese Patent Laid-open Publication No. Hei. 6-60153) capable of automatically generating a solid model realizing the three-dimensional shape of an object from two-dimensional CAD drawings drawn in three planes.
This conventional method of generating three-dimensional figure data is suitable for generating three-dimensional figure data based on, for example, two-dimensional figure data relating to an orthogonal XYZ coordinate system, i.e. data relating to plane shapes of objects, data relating to front shapes of objects or data relating to side shapes of objects. However, in the case where figure data relating to planes of other coordinate systems, for example, figure data relating to planes taking an axis at a position that is skewed with respect to the orthogonal XYZ axes or figure data relating to partially projected views (section views) where an object is viewed from an arbitrary direction is included, concave closed loop processes or assistance line processing and concealed line processing becomes difficult, with further complications resulting from the bulkiness of attribute information are also possible.
The input work for this kind of conversion to a three-dimensional CAD drawing is inefficient. Furthermore, the amount of work for the CAD operators and the operation processing steps in the program are constantly increasing. Therefore, when servicing the working environment and system maintenance etc. are considered, there is a demand for a three-dimensional CAD system and a method for converting two-dimensional CAD drawings to three-dimensional CAD drawings capable of both alleviating the amount of work for the operators and shortening the operation time as well as reducing the operation processing steps of the program regardless of the kind of two-dimensional figure data.
SUMMARY AND OBJECT OF THE INVENTION
It is an object of the present invention to solve the above-mentioned problems.
It is another object of the present invention to provide a three-dimensional CAD system and method of converting from two-dimensional CAD drawings to three-dimensional CAD drawings capable of dramatically shortening the time for making three-dimensional CAD drawings from two-dimensional CAD drawings and simplifying both the inputting work for CAD operators and the operation processing of the program regardless of the kind of two-dimensional figure data.
The three-dimensional CAD system is therefore configured with a data reading unit for reading two-dimensional CAD data made by a two-dimensional CAD system, a figure allotting unit for allotting a plurality of figures formed of read-in two-dimensional CAD data to at least two reference planes, an outermost contour line extracting unit for extracting outermost contour lines for each figure occurring at the reference planes allotted to the figures, a solid element making unit for making solid elements for shapes extended in a direction normal to the reference planes corresponding to the extracted outermost contour lines, and a solid element synthesizing unit for synthesizing made plurality of solid elements so as to make three-dimensional CAD data based on the two-dimensional CAD data.
In this way, two-dimensional data made by the two-dimensional CAD system is first read-into the three-dimensional CAD system via the data reading unit. The plurality of figures formed for this read-in binary CAD data are then allotted to at least two reference planes via the figure allotting means. Namely, the two-dimensional CAD data is figure data obtained by making the product shape conform to various technical drawings. This therefore typically includes, for example, figure data conformed to the plane shape, front shape and side shape of a product; figure data relating to planes occurring on other coordinate systems or figure data relating to planes taking an axis that is skewed with respect to, for example, the XYZ axes as a normal.
Therefore, in, for example, the case of using the figure allotting unit, two-dimensional CAD data relating to the plane shape of the product would be allotted as figure data taking, for example, the xy plane as a reference plane, the two-dimensional CAD data relating to the front shape of the product would be allotted as shape data taking the xz plane as a reference plane, and two-dimensional CAD data relating to the side shape of the product would be taken as shape data taking, for example, the yz plane as a reference plane.
Further, in addition to figure data relating to the xy plane, yz plane and xz-plane occurring in the orthogonal XYZ coordinate system, the figure allotting unit also carries out allotting for figure data relating to, for example, planes taking an axis skewed with respect to the orthogonal XYZ axis as a normal and for figure data relating to section views where a certain product is viewed from an arbitrary direction. In this case, the respective reference planes correspond to planes taking an axis at a skewed position as a normal and, for section views, planes taking the direction of projection as a normal.
The outermost contour lines (outer shape lines) of the respective shapes for each reference plane are then extracted via the outermost contour line extracting unit based on the shape data allotted to each reference plane. Lines for detailed parts included in the outermost contour lines such as, for example, circular lines indicating holes or lines indicating projections are deleted at this extracting stag
Honda Giken Kogyo Kabushiki Kaisha
Nguyen Thu
Powell Mark R.
LandOfFree
Three-dimensional CAD system and method of converting... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Three-dimensional CAD system and method of converting..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Three-dimensional CAD system and method of converting... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2512788