Search results for "3D modeling"
showing 10 items of 68 documents
Improving light propagation Monte Carlo simulations with accurate 3D modeling of skin tissue
2008
In this paper, we present a 3D light propagation model to simulate multispectral reflectance images of large skin surface areas. In particular, we aim to simulate more accurately the effects of various physiological properties of the skin in the case of subcutaneous vein imaging compared to existing models. Our method combines a Monte Carlo light propagation model, a realistic three-dimensional model of the skin using parametric surfaces and a vision system for data acquisition. We describe our model in detail, present results from the Monte Carlo modeling and compare our results with those obtained with a well established Monte Carlo model and with real skin reflectance images.
Real-time characterization of aspect flaws on warped surface by artificial vision
1997
Artificial vision is an efficient means of assuring the quality of a certain class of products. The vision system must respect the industrial constraints, in particular, the production rate. The geometrical features of flaws are pertinent information used for the acceptance of the controlled product. This article presents a real-time algorithm for the geometrical characterization of defects located on warped objects. The algorithms described enable the characterization of defects by their size and their 2-D shape. Both parameters are calculated in real time by simple reference to a look-up table. The 2-D shape is obtained by a geometrical transform and an interpolation. The efficiency of th…
Coarse to fine : toward an intelligent 3D acquisition system
2015
International audience; The 3D acquisition-compression-processing chain is , most of the time , sequenced into independent stages. As resulting , a large amount of 3D points are acquired whatever the geometry of the object and the processing to be done in further steps. It appears , particularly in mechanical part 3D modeling and in CAD , that the acquisition of such an amount of data is not always mandatory. We propose a method aiming at minimizing the number of 3D points to be acquired with respect to the local geometry of the part and therefore to compress the cloud of points during the acquisition stage. The method we propose is based on a new coarse to fine approach in which from a coa…
Accelerating orthodontic tooth movement: a new, minimally-invasive corticotomy technique using a 3D-printed surgical template
2015
Background A reduction in orthodontic treatment time can be attained using corticotomies. The aggressive nature of corticotomy due to the elevation of muco-periosteal flaps and to the duration of the surgery raised reluctance for its employ among patients and dental community. This study aims to provide detailed information on the design and manufacture of a 3D-printed CAD-CAM (computer-aided design and computer-aided manufacturing) surgical guide which can aid the clinician in achieving a minimally-invasive, flapless corticotomy. Material and Methods An impression of dental arches was created; the models were digitally-acquired using a 3D scanner and saved as STereoLithography ( STL ) file…
Conjectural reconstruction from archive drawings: methodological aspects
2018
The digital reconstruction of architectural projects starting from archive sources is a well established disciplinary application useful for the study and analysis of architecture and its relations with the historical context as well as for the representation of volumes and spaces not visible in the original documents. Given the importance recognized to these operations which inevitably involve processes of hermeneusi we propose methodological guidelines for the drafting a protocol limiting arbitrariness as much as possible. The analysis was carried out on three projects by Giuseppe Damiani Almeyda (Capua 1834 - Palermo 1911), Ernesto Basile (Palermo 1857-1932) and Salvatore Benfratello (Pa…
BIM e beni architettonici: verso una metodologia operativa per la conoscenza e la gestione del patrimonio culturale. BIM and architectural heritage: …
2016
The study aims to answer the growing need for virtuously organize informational apparatuses related to Cultural Heritage. We propose a methodology that integrates multidisciplinary processes of interaction with information aimed at survey, documentation, management, knowledge and enhancement of historic artifacts. It is needed to review and update the procedure of instrumental data acquisition, standardization and structuring of the acquired data in a three-dimensional semantic model as well as the subsequent representability and accessibility of the model and the related database. If the use of Building Information Modeling has in recent years seen a consolidation in the procedures and the…
Using dense stereo matching techniques in survey
2013
In recent years there has been an enormous increase in the dissemination of modelling techniques known as dense stereo matching (DSM) or image-based modelling (IBM) using free, low cost, open source software, especially applications involving the survey of cultural heritage (architecture, archaeology, and town planning). The algorithms used by these software programmes process photographic datasets and provide a 3D model of the scene in question. During complex survey and 3D restitution procedures, these techniques save time (processing) and money: these advantages Can he useful to any professional. This is why it is important to identify the real potential and limits of these software prog…
Un'occasione perduta: l'Eden Teatro Biondo di Ernesto Basile. Dai disegni di archivio alla ricostruzione digitale
2016
Il lavoro si pone come obiettivo la ricostruzione congetturale del progetto dell’Eden Teatro Biondo (1912) a Palermo di Ernesto Basile (Palermo 1857–1932) a partire dai disegni originari. L’edifico propone una tipologia che fonde cinematografo (al piano terra) e teatro (al piano superiore). Pensato su un fronte di Piazza Verdi, non sarà realizzato per i costi ritenuti troppo elevati dai committenti. Le scansioni dei disegni originari (conservati presso il Fondo Basile del Dipartimento di Architettura dell’Università di Palermo) hanno consentito la vettorializzazione piana utilizzata per l’analisi e per la modellazione 3D. Gli apparati decorativi sono stati realizzati integrando la modellazi…
Augmented Reality Aided 3D Modelling
2014
The purpose of the article is to introduce possibilities of using Augmented Reality instructions in order to better understand technical drawings. The aim of these instructions based on 3D models is to create AR training applications and analyze their impact on the users. These instructions consist in a 3D model, superimposed over the technical drawing. The AR application also offers step by step instructions for 3D modelling in CAD software, which are very useful in creating the 3D model starting from a technical drawing. The AR application was tested by students from the Faculty of Engineering in Sibiu, obtaining great improvements in their 3D modelling times. The results of a survey that…
Hand Held 3D Scanning for Cultural Heritage: Experimenting Low Cost Structure Sensor Scan
2017
In the last years 3D scanning has become an important resource in many fields, in particular it has played a key role in study and preservation of Cultural Heritage. Moreover today, thanks to the miniaturization of electronic components, it has been possible produce a new category of 3D scanners, also known as handheld scanners. Handheld scanners combine a relatively low cost with the advantage of the portability. The aim of this chapter is two-fold: first, a survey about the most recent 3D handheld scanners is presented. As second, a study about the possibility to employ the handheld scanners in the field of Cultural Heritage is conducted. In this investigation, a doorway of the Benedictin…