3D Sketching for aesthetic design using Fully Free Form Deformation Features

This paper addresses the designers’ activity and in particular the way designers express an object shape in 2D sketches through character lines and how these lines form a basis for sketching shapes in 3D. The tools currently available in commercial CAS/CAD systems to manipulate the digital models are still not sufficiently suited to support design. In this paper, the so-called fully free-form deformation features (d-F4) are introduced as a modelling method to take into account the curve-oriented stylists’ way of working. Both the advantages of a free-form surface deformation method and a feature-based approach are merged to define these high-level modelling entities allowing for a direct manipulation of surfaces through a limited number of intuitive parameters. Such features incorporate several characteristics designed to handle the uncertainties and/or inconsistencies of the designer’s input during a sketching activity. In addition, a d-F4 classification is proposed to enable a fast access to the desired shape according to its semantics and characteristics.The work is being carried out in the scope of the activity of AIM@SHAPE Network of Excellencesupported by the European Commission, VI Framework, IST Contract No. 506766

A survey to evaluate how non designers perceive aesthetic properties of styling features

World-wide market competition and the need to create products that better satisfy the market expectations require a more comprehensive involvement of the customer in the product definition loop. Therefore, it is crucial to provide customers with very easy-to-use shape definition and modification tools, allowing them to verify and evaluate possible shape alternatives without requiring specific knowledge on geometric modeling. A set of aesthetic properties guiding the shape characterization and appraisal have been identified together with measures for their evaluation and shape modeling methods for their direct modification. Since these properties have been indicated by stylists, no guarantee exists that they are usable in a context directly involving customers in the product definition loop. To verify the extent to which the terms indicating the properties, their meaning and their measures are significant and understandable by non-expert designer people we carried out a survey. This paper describes the methodology adopted and the outcomes of this survey

A multi-perspective dynamic feature concept in adaptive NC machining of complex freeform surfaces

This paper presents a new concept of feature for freeform surface machining that defines the changes in feature status during real manufacturing situations which have not been sufficiently addressed by current international standards and previous research in feature technology. These changes are multi-perspective, including (i) changes in depth-of-cut: the geometry of a feature in the depth-of-cut direction changes during different machining operations such as roughing, semi-finishing and finishing; (ii) changes across the surface: a surface may be divided into different machining regions (effectively sub-features) for the selection of appropriate manufacturing methods for each region such as different cutting tools, parameters, set-ups or machine tools; and (iii) changes in resources or manufacturing capabilities may require the re-planning of depth-of-cuts, division of machining regions and manufacturing operations (machines, tools, set-ups and parameters). Adding the above dynamic information to the part information models in current CAD systems (which only represent the final state of parts) would significantly improve the accuracy, efficiency and timeliness of manufacturing planning and optimisation, especially for the integrated NC machining planning for complex freeform surfaces. A case study in an aircraft manufacturing company will be included in this paper

Semantic Evaluation and Deformation of Curves Based on Aesthetic Criteria

To better simulate the way designers work, specific tools are needed to handle directly specific shape features meaningful for the design intent, without focusing on the underlying mathematic representation. For this purpose it is fundamental to identify proper higher-level shape descriptors as well as the corresponding manipulation techniques. The paper presents the definition and implementation of semantic operators for curve deformation based on a shape characterization that is specific to the industrial design context. The work grounds on the innovative approach suggested by the FIORES-II project for the intent-driven modeling tools for direct shape modification and on the multi-layered architecture proposed by the Network of Excellence AIM@SHAPE for the definition of semantic-oriented 3D models. In particular the paper proposes the use of meaningful aesthetic features for the evaluation of planar curve signature and for their intent-driven direct modification

3D Sketching for aesthetic design using Fully Free Form Deformation Features

International audienceThis paper addresses the designers’ activity and in particular the way designers express an object shape in 2D sketches through character lines and how these lines form a basis for sketching shapes in 3D. The tools currently available in commercial CAS/CAD systems to manipulate the digital models are still not sufficiently suited to support design. In this paper, the so-called fully free-form deformation features (d-F4) are introduced as a modelling method to take into account the curve-oriented stylists’ way of working. Both the advantages of a free-form surface deformation method and a feature-based approach are merged to define these high-level modelling entities allowing for a direct manipulation of surfaces through a limited number of intuitive parameters. Such features incorporate several characteristics designed to handle the uncertainties and/or inconsistencies of the designer’s input during a sketching activity. In addition, a d-F4 classification is proposed to enable a fast access to the desired shape according to its semantics and characteristics

An evaluation of user experience with a sketch-based 3D modeling system

Abstract With the availability of pen-enabled digital hardware, sketch-based 3D modeling is becoming an increasingly attractive alternative to traditional methods in many design environments. To date, a variety of methodologies and implemented systems have been proposed that all seek to make sketching the primary interaction method for 3D geometric modeling. While many of these methods are promising, a general lack of end user evaluations makes it difficult to assess and improve upon these methods. Based on our ongoing work, we present the usage and a user evaluation of a sketch-based 3D modeling tool we have been developing for industrial styling design. The study investigates the usability of our techniques in the hands of non-experts by gauging (1) the speed with which users can comprehend and adopt to constituent modeling steps, and (2) how effectively users can utilize the newly learned skills to design 3D models. Our observations and users' feedback indicate that overall users could learn the investigated techniques relatively easily and put them in use immediately. However, users pointed out several usability and technical issues such as difficulty in mode selection and lack of sophisticated surface modeling tools as some of the key limitations of the current system. We believe the lessons learned from this study can be used in the development of more powerful and satisfying sketch-based modeling tools in the future.

DEVELOPMENT OF CLASSIFICATION METHODOLOGY OF PERCEPTIONAL SURFACES IN PRODUCT DESIGN

Disertacija obravnava problematiko vrednotenja površja. To površje je lahko elementarna ploskev, ploskev, sestavljena iz elementarnih ploskev, 3D skenogram ali mrežni model. Uporabljamo izraz zaznavne ploskve, ki predstavljajo površje, ki ključno vpliva na zaznavanje izdelka z uporabniškega vidika. Pri tem nas ne zanima estetska vrednost teh ploskev, ampak metodologija, ki omogoča vrednotenje. Za ta namen smo predstavili metodologijo n×n, ki se izvaja hkrati v programskem okolju Rhinoceros (RH) in dodatku Grasshopper (GH). V GH je nastavljena procedura z uporabo standardnih gradnikov GH. Rezultat te analize je najprej n×n matrika, v kateri so zbrane n×n razdalje, ki so v nadaljevanju normirane in zbrane v normalizirani n×n matriki. Iz normirane n×n matrike izhajajo izračuni za lastnosti CASP. S temi štirimi lastnostmi lahko ovrednotimo vsako površjeoznačujejo pa ukrivljenost, pospešenost, simetrijo in proporcionalnost. Rezultati so primerljivi samo pri elementarnih ploskvah. Elementarna ploskev je ploskev, ki ima podobno ukrivljenost ali predstavlja oblikovno značilnost ali del oblikovne značilnosti. Pri kompleksnih ali sestavljenih ploskvah lahko rezultate primerjamo samo za določen tip objektovna primer samo za obraze. Sicer kompleksne ploskve segmentiramo in razdelimo na elementarne. Prikazanih je tudi nekaj vmesnih razvojnih faz, v katerih smo uporabili drugačne analitične postopke, ki smo jih na koncu opustili. Vseeno lahko z njimi analiziramo geometrijo, le povezati in aktivirati je potrebno ustrezne gradnike v GHkot je recimo izris in analiza linije prereza ali prerez dveh prostorskih teles. V eksperimentalnem delu je zbranih nekaj praktičnih primerov uporabe CASP in postopki za izboljšavo dizajnerskega procesa za nadaljnjo uporabo. Prikazana je uporaba CASP metode na sedežih profesionalnih tekmovalnih koles, na računalniških miškah, na obrazih, na zadku avtomobila Tushek & Spigel – TS 600 in na obrezilnih orodjih za industrijske stiskalnice. Predstavljena je metoda, ki smo jo poimenovali DEGI, kjer uporabimo obstoječo geometrijo in jo vgradimo v nov izdelek.This work deals with the problem of surface evaluation. The surface can be elementary surface or surface compound of several elementary surfaces. It can also be 3D scan or any mesh model. Term perceptional surface is used to present surface that has key impact on perception of a product. At this point the aesthetic value is not important, however we are interested in the methodology which enables the evaluation. N×n, methodology is introduced, which runs within computer modeller Rhinoceros (RH) and its add-in Grasshopper (GH). In GH the procedure with standard GH components is set as a base. The result of this analysis is in first place the n×n matrix where n×n distances are collected and normalized alter on in normalized n×n matrix. From normalized n×n matrix the CASP properties are calculated. By using these four properties any surface can be evaluated. Term CASP stands for curvature, acceleration, symmetry and proportionality. The results are comparable only for elementary surfaces. Elementary surface is a surface with similar curvature or presents same shape feature or a part of it. For complex and compound surfaces the results can be compared merely for specific types of objects, e.g. just for human faces. Otherwise the compound surface can be segmented into elementary surfaces. Several intermediate evolutional phases are shown, but were later excluded from further research. Anyhow, different geometries can be analysed with proper components adjustment in GH that should be connected and activated, e. g. intersection line creation and analysis or intersection of two geometrical bodies. In the experimental part, the CASP methodology is represented by using concrete examples, in addition, some steps for design process improvement in future work are listed. The CASP methodology is shown on professional bike seats, on computer mice, on human faces, on Tushek & Spigel – TS 600 sports car tail and on cutting tools for industrial presses. At the end, the method we called DEGI is shown, where existing geometry is used and implemented in some newly created product

Diagnostic study on shape perception errors within 3D-modeling courses

Form has always been a central concern for design -- Several tools and strategies have been developed aiming to support form generation from different perspectives -- And these issues are also a matter of study for design education -- Under this view, it is relevant to explore how technology and new interactions can aid design students to better understand form generation -- The present study, therefore, is centered on the 3D-modeling courses (ID0245-Modelación 3D1 and ID0267- Modelación 3D2) and tools (PTC® Creo 3.0™) provided inside the Product Design Engineering syllabus at EAFIT University -- In the ever changing academic world, new generations of students will be always in need of new methodological approaches from educators, in order to better understand the knowledge they are being given -- Curriculum adaptations will be always necessary to achieve this goal -- Therefore, the scope of the present study aims to set the ground for new teaching strategies around the 3D-modeling courses, based on the most commonly identified errors and difficulties found in 3D-modeling students -- These errors or difficulties might not be isolated factors, only present in the named courses -- They can be intrinsically connected with the acquired skills from other form generation-related courses, such as Drawing and Projects (where physical model are built and techniques are introduced by guidance) -- However, since the project is framed by the mentioned 3D-modeling tools and courses, it is necessary to understand how form is being generated inside 3D digital environments as a starting point for future work -- Nowadays, individual software provide increasing capabilities to help achieving specific modeling tasks -- This segmentation and specialization demands high expertize from users to become accustomed and keep up with the ever demanding industry standards -- Nonetheless, speed and quality cannot be compromised -- Hence, the main target around the study will be design students that take their first steps towards product embodiment -- The project, therefore, aims to understand how students approach styling activities and to report on their most common mistakes -- It is based on how they perceive 2D representations of products and how accurate their 3D-models are, based on selected shape properties -- This will serve as an essential input for new teaching strategies towards students’ self-awareness when performing in 3D form-giving environment

Sketching apoyado en computación: Determinación de las características y atributos que permiten la eficiencia de herramientas tecnológicas en la etapa creativa del proceso de diseño de producto

153 páginas. Doctorado en DiseñoToday it is possible to affirm that the designers can materialize and develop their first ideas without paper and pencil. This is possible due to the latest technological advances in the field of design software and processing devices. The overall objective of this thesis is to analyze the characteristics and attributes that allow certain technological tools support the creative stage of product design process. The specific objectives are the following: identify the different types of representations used in the product design process, emphasizing the main features and characteristics of the sketch; describe the different types of technological tools used in the product design process, especially those likely to be used in the creative stage; and finally, to develop a tool to do a study which evaluates efficiency of three computer programs most used in the creative phase of the design process, through an exercise of representation and conceptual exploration. Given that this problem has been poorly studied, the pilot study was exploratory and quantitative- qualitative approach, focusing on the ability to represent the first ideas in selected computer programs, leaving aside everything related to the mental activity of the designer. Based on the study, we can say that there are a number of features and attributes that allow certain technological tools are efficient for representation and development of the first ideas in the creative stage of product design. However, it should be noted that these results are inconclusive, because it would require a larger sample, but this study will serve as a starting point for further research.Hoy en día es posible afirmar que el diseñador puede prescindir del papel y lápiz para aterrizar y desarrollar sus primeras ideas. Esto es posible debido a los últimos avances tecnológicos en materia de programas computacionales y dispositivos de procesamiento. El objetivo general de la presente tesis es analizar las características y atributos que permiten a ciertas herramientas tecnológicas soportar la etapa creativa del proceso de diseño de producto. Como objetivos específicos, por su parte, se consideran los siguientes: identificar los diferentes tipos de representaciones utilizadas en el proceso de diseño de producto, haciendo énfasis en las principales propiedades y características del sketch; describir las diferentes tipos de herramientas tecnológicas utilizadas en el proceso de diseño de producto, en especial las susceptibles de ser utilizadas en la etapa creativa del proceso de diseño de producto; por último, desarrollar un instrumento para elaborar un experimento, el cual pretende evaluar la eficiencia de tres de los programas computacionales más utilizados en la etapa creativa del proceso de diseño, mediante un ejercicio de representación y exploración conceptual. Dado que este problema ha sido poco estudiado, el experimento realizado fue de tipo exploratorio y con un enfoque cuanti-cualitativo, centrándose en la capacidad de representación de las primeras ideas en los programas computacionales seleccionados, dejando de lado todo lo relacionado con la actividad mental del diseñador. Con base en este estudio, podemos afirmar que el instrumento desarrollado resultó adecuado para su propósito y que, en cuanto a los programas estudiados, existen una serie de características y atributos que permiten que ciertas herramientas sean eficaces para la representación y desarrollo de las primeras ideas en la etapa creativa del proceso de diseño de producto. Sin embargo, es necesario precisar que estos resultados nos son concluyentes, pero sin duda este experimento servirá como punto de partida para investigaciones posteriores