Abstract: A method of operating a computer aided design (CAD) system model for modelling an article to be manufactured includes receiving a representation of the article, receiving constraints for the article, determining a maximum permissible curvature of one or more parts of the article, measuring the maximum curvature of the one or more parts of the article in the received representation and comparing the measured maximum curvature with the maximum permissible curvature. If the measured maximum curvature of at least one of the one or more parts exceeds the determined maximum permissible curvature, an error indication is provided. If the measured maximum curvature of each of the one or more parts does not exceed the determined maximum permissible curvature, the received representation for the article is stored.

Abstract: A method of operating a computer aided design (CAD) system model for modelling an article to be manufactured includes receiving a representation of the article, receiving constraints for the article, determining a maximum permissible curvature of one or more parts of the article, measuring the maximum curvature of the one or more parts of the article in the received representation and comparing the measured maximum curvature with the maximum permissible curvature. If the measured maximum curvature of at least one of the one or more parts exceeds the determined maximum permissible curvature, an error indication is provided. If the measured maximum curvature of each of the one or more parts does not exceed the determined maximum permissible curvature, the received representation for the article is stored.

Abstract: Systems, methods, and computer program products for identifying under-defined geometries due to singular constraint schemes. A method includes receiving a CAD model having a plurality of geometries and determining the degrees of freedom for each of the geometries. The method includes identifying a number of constraints on each of the geometries and identifying any of the geometries that are under-defined and any of the geometries that are well-defined. The method includes identifying any of the under-defined geometries that are under-defined due to singular (UDS) and storing a UDS indicator for each of the geometries identified as UDS. The method can include identifying geometries computed from these UDS geometries (CFS) and storing a CFS indicator for each of the geometries identified as CFS.

Abstract: Systems, methods, and computer program products for identifying under-defined geometries due to singular constraint schemes. A method includes receiving a CAD model having a plurality of geometries and determining the degrees of freedom for each of the geometries. The method includes identifying a number of constraints on each of the geometries and identifying any of the geometries that are under-defined and any of the geometries that are well-defined. The method includes identifying any of the under-defined geometries that are under-defined due to singular (UDS) and storing a UDS indicator for each of the geometries identified as UDS. The method can include identifying geometries computed from these UDS geometries (CFS) and storing a CFS indicator for each of the geometries identified as CFS.

Abstract: A colored acrylic sheet having an attractive 3-dimensional depth of color resulting from the use of a mixture of pigments or a pigment and a dye wherein an inorganic pigment, distributed non-uniformly throughout the sheet and a colorant is distributed uniformly through the sheet, the particles of non-uniformly distributed pigment being concentrated preferentially towards one surface of the sheet and are visible through the opposite surface of the sheet which is preferably substantially free from the non-uniformly distributed pigment. The attractive appearance is further enhanced by shaping the sheet and the sheet is particularly suitable for forming articles of sanitaryware.