geoTangle : Interactive Design of Geodesic Tangle Patterns on Surfaces

Tangles are complex patterns, which are often used to decorate the surface of real-world artisanal objects. They consist of arrangements of simple shapes organized into nested hierarchies, obtained by recursively splitting regions to add progressively finer details. In this article, we show that 3D digital shapes can be decorated with tangles by working interactively in the intrinsic metric of the surface. Our tangles are generated by the recursive application of only four operators, which are derived from tracing the isolines or the integral curves of geodesics fields generated from selected seeds on the surface. Based on this formulation, we present an interactive application that lets designers model complex recursive patterns directly on the object surface without relying on parametrization. We reach interactive speed on meshes of a few million triangles by relying on an efficient approximate graph-based geodesic solver.

Diagram Drawing Using Braille Text

This chapter presents a novel system for drawing geometric diagrams on the Braille medium in order to make the diagrams tactile and accessible by blind people. The computer graphics algorithms for drawing digital shapes have been suitably modified to make them work for the Braille environment. The goodness of the diagrams is measured by quantifying approximation errors in these diagrams. This chapter further demonstrates how computational intelligence can be embedded in the system to develop an intelligent teaching-learning aid for the blind, especially for teaching them figure-based subjects like geometry, physics, engineering, drawing, etc.

The Role of Designer-Customer Collaboration for Product Customization and Assessment

This paper addresses issues related to the assessment of product designs that today successfully uses virtual prototyping methods and techniques. Design assessment is usually performed by engineers and designers. Current trend is involving customers in the products design assessment in order to check the level of acceptability and satisfaction before proceeding with the production. In this view, methods for design review may be used in participatory design sessions where customers can intervene for customizing products. The paper presents a tool that has been originally developed for designers for the validation and modification of aesthetic properties of digital shapes, and that has also been used by customers, in participatory design sessions, for customizing their products.