FlowRep

Abstract

We present FlowRep , an algorithm for extracting descriptive compact 3D curve networks from meshes of free-form man-made shapes. We infer the desired compact curve network from complex 3D geometries by using a series of insights derived from perception, computer graphics, and design literature. These sources suggest that visually descriptive networks are cycle-descriptive , i.e their cycles unambiguously describe the geometry of the surface patches they surround. They also indicate that such networks are designed to be projectable , or easy to envision when observed from a static general viewpoint; in other words, 2D projections of the network should be strongly indicative of its 3D geometry. Research suggests that both properties are best achieved by using networks dominated by flowlines , surface curves aligned with principal curvature directions across anisotropic regions and strategically extended across sharp-features and isotropic areas. Our algorithm leverages these observation in the construction of a compact descriptive curve network. Starting with a curvature aligned quad dominant mesh we first extract sequences of mesh edges that form long, well-shaped and reliable flowlines by leveraging directional similarity between nearby meaningful flowline directions We then use a compact subset of the extracted flowlines and the model's sharp-feature, or trim, curves to form a sparse, projectable network which describes the underlying surface. We validate our method by demonstrating a range of networks computed from diverse inputs, using them for surface reconstruction, and showing extensive comparisons with prior work and artist generated networks.

CAD2Sketch

“…In contrast, we take as input CAD sequences that already contain intermediate geometric primitives, and we leverage the common visual vocabulary of CAD modeling and concept sketching to convert CAD operations into sketching steps not covered by Hennessey et al [2016]. Our work also relates to the algorithms proposed by Schmidt et al [2007] and Gori et al [2017], who take inspiration from sketching techniques to depict smooth surfaces using planar sections and other curvature-aligned curves. But these methods do not consider the intermediate constructions lines that characterize concept sketches in industrial design.…”

“…While our system supports common CAD operations and the corresponding construction lines, it could be extended to cover more diverse shapes. In particular, freeform shapes are often created by lofting CAD profiles, which designers typically sketch using planar cross-sections and other flow-lines [Gori et al 2017]. Currently, we only render grid and feature lines for such operations, see Fig.…”

“…Since our system does not add any construction lines for these operators, the result is solely made out of profile lines, grid lines and feature lines (b). Professional designers typically add curvature-aligned flow-lines to depict such smooth surfaces[Gori et al 2017].…”

Ferramentas De Apoio Ao Ensino Do Sketching: Um Panorama Recente

“…Mesmo assim, achamos importante citá-lo por sua possível contribuição para o futuro do sketching. Trata-se de um algoritmo, capaz de "descrever" os parâmetros geométricos de um modelo digital, oferecendo informações precisas sobre a forma (GORI et al, 2017). Na figura, a seguir, é mostrado um comparativo (ver figura 2).…”

Modern graphic design application innovation based on graphic abstract processing method

“…The designer should have a keen insight to outline creative graphics through the use of different lines [16] and combine with the public's understanding of graphic design to reasonably select the design graphics, or also through the use of harmonies, associations, and metaphors. The elements can be further processed and configured from a different points of view, fields, and levels to show the artistic value of graphic design and leave a deep impression on the audience [17][18][19]. In addition, modern art design shows more freedom, which requires designers to imagine freely, not to be limited by the traditional thinking of graphic design, but also to have the courage to break through the traditional design concepts of the spirit of innovation and creativity, to seize the inspiration of the design, and to effectively integrate the design materials.…”