Abstract: A computer-assisted design apparatus and method for flattening a three-dimensional surface region to a two-dimensional shape in a flat plane or for wrapping a two-dimensional shape to a three-dimensional surface region. A mesh is grown on the surface to be wrapped or unwrapped. The polygonal elements of the mesh are mapped to a growing surface, which is independent of the three-dimensional surface. The growing surface is rotated and translated in order to position the polygonal elements on the two-dimensional surface, for unwrapping, or adjacent to the three-dimensional surface, for wrapping. For unwrapping and flattening, the mesh is grown on the three-dimensional surface region to be unwrapped and flattened independent of the surface boundaries of the parametric spline patch surfaces joined together to form the three-dimensional surface region. In this manner, the resulting mesh spans the mathematical definition of the corresponding surfaces.

Abstract: A system and method for providing surface detail to mathematically defined three-dimensional surfaces which preserves the specific dimensional integrity of the surface detail image being mapped to provide dimensionally correct surface detail. This is accomplished by performing the intermediate step of mapping the surface detail image to a two-dimensional flattened pattern piece representation of the surface and thereafter mapping this representation to the three-dimensional surface. The system and method of the present invention may be used as one function of a greater three-dimensional computer aided design system for any industry which utilizes flat sheets of material formed or assembled into a finished product including textiles, apparel, footwear, upholstered furnishings, automotive or interior design.

Abstract: A method and system for alternatingly applying different colors to a realistic computer generated graphic image while preserving the effects of shading, highlights, reflectors and other lighting effects. A user selects a "New Color" to apply to an image and picks an "Original Color" from the image in an area not subject to extreme lighting effects. The difference between the parameters of these two colors in (H,S,V) coordinates is determined and applied to every pixel in a segment of the image to calculate a replacement pixel color. Tools are provided to allow the user to divide an image into segments to which color modification can be individually applied.

Abstract: A system and method for correcting errors in the colors of an image in a computer-aided design system; such errors being introduced by a process such as the production of a hard-copy of an image displayed on a graphic CRT. Tools are provided for the user to select "registered" colors and to determine, either manually or by system calculation, corrected values of such registered colors that will produce the desired image on the hard-copy. The manual selection technique provides tools for iteratively creating charts of related, but varied, color squares and sending the charts to the output device. The resulting hard-copy is compared by the user with the chart displayed on the CRT and the user's selection is processed by the system. In the other technique, the hard-copy image of such color chart is re-entered to the system through an input device and the error between the original and processed color patches is calculated and applied to determine corrected colors.

Abstract: A system and method for use with a two-dimensional CAD system for rapidly applying surface detail, such as various patterns, to a 2-D image in a manner to provide a 3-D appearance. During a preprocessisng step, a 2-D image to which a perspective mesh has been applied, is scanned pixel-by-pixel and several tables are built of data derived from parameters of each pixel. The tables are used during a fast mapping step to apply pixels making up the surface detail or pattern very rapidly without compromising the visual appearance of the resulting image. One table is built of the two-dimensional offsets of image pixels from references in the mesh grid and is used to map to a pair of one-dimensional tables specific to a selected pattern array to select offset coordinates for mapping quickly to the appropriate pattern pixels.

Abstract: A method and apparatus for flattening a three-dimensional surface into a two-dimensional pattern piece extracts a three-dimensional mesh from the surface to define surface elements and maps these elements in groups to a flat plane where they are reassembled. The position of data points in the flat plane are recursively adjusted in order to cancel error and to provide an optimum solution. Tools are provided to the user to determine the correctness of the flattening process and to insert darts into, and make other modifications to, the resulting flat pattern in order to further optimize the result.

Abstract: A realistic image of woven cloth surface is provided by a system which receives a user input of a yarn cross section design to produce a side view image of a resultant spun or unspun yarn and which utilizes either basic weave patterns or user-designed patterns to produce a woven cloth images. Shading is applied to the cross-sectional image of each fiber selected in a yarn to provide a realistic image of the resultant spun-yarn. Shading is also applied to portions of each warp and fill thread in the vicinity of their intersecting each other to provide a realistic woven fabric surface image.