Applications of Ray Tracing

The present work carries out static and kinematical studies of both front and rear suspensions of a brazilian medium sized passenger car.The concept of virtual prototyping with the use of multibody system modelling t echniques is employed by ADA..l\tlS, a package developed by Mechanical Dynamics Inc..The concept of v irtual prototyping allows vehicle development without the need of physical prototypes construction.ADAMS uses the description of t he geometric suspension, inertia parameters from its parts and how the parts are connected to generate a full model of the system.The type of analysis which can carry out include vertical and steering behaviour (in the case of a front suspension).These analysis are generated in graphical as well as and animation.These results are included among others: toe-in angle; camber and caster angle; kingpin inclination, scrub radius, and so forth.The use of the virtual prototyping concept, has m ade easier the modelling and analysis of this type of mechanism.This indicates the possibility of shortening product development times or altering product behaviour with a small effort.

End-to-end modeling of the photometric performance of LCD projection system using Monte Carlo geometrical ray tracing methods is an accurate and precise tool for predicting and improving the performance of these deices before, during and after product development. However, an accurate simulation first requires considering which physical properties contribute most to the system's photometric performance. Second, these properties must be characterized by physical measurements and translated into the tangible modeling parameters of a ray tracing program. Third, the implications of using a Monte Carlo ray tracing algorithm, and in general any other optical transformation algorithm, on radiometric accuracy must be well understood. These considerations as well as a generalized approach to the characterization and simulation of an LCD projector are described. A commercially available ray tracing program, the Advanced Systems Analysis Program, is used to demonstrate this approach. The irradiance uniformity, CIE color performance and screen brightness of an arc source LCD projector system are computed as an example.

The application scenarios and requirements are more diverse in the fifth-generation (5G) era than before. In order to successfully support the system design and deployment, accurate channel modeling is important. Ray-tracing (RT) based deterministic modeling approach is accurate with detailed angular information and is a suitable candidate for predicting time-varying channel and multiple-input multiple-output (MIMO) channel for various frequency bands. However, the computational complexity and the utility of RT are the main concerns of users. Aiming at 5G and beyond wireless communications, this paper presents a comprehensive tutorial on the design of RT and the applications. The role of RT and the state-of-the-art RT techniques are reviewed. The features of academic and commercial RT based simulators are summarized and compared. The requirements, challenges, and developing trends of RT to enable the visions are discussed. The practices of the design of high-performance RT simulation platform for 5G and beyond communications are introduced, with the publicly available high-performance cloud-based RT simulation platform as the main reference. The hardware structure, networking, workflow, data flow and fundamental functions of a flexible high-performance RT platform are discussed. The applications of high-performance RT are presented based on two 5G scenarios, i.e., a 3.5 GHz Beijing vehicle-to-infrastructure scenario and a 28 GHz Manhattan outdoor scenario. The questions on how to calibrate and validate RT based on measurements, how to apply RT for mobile communications in moving scenarios, and how to evaluate MIMO beamforming technologies are answered. This tutorial will be especially useful for researchers who work on RT algorithms development and channel modeling to meet the evaluation requirements of 5G and beyond technologies.

During the New Product Development (NPD) cycle, it is important to focus and integrate relevant information into the stages of product conceptualisation, design and development so that they can be used for product and process design effectively. In this paper, a Generic Product and Process Development System (GPDS), which integrates knowledge-based technologies of Rule-Based Expert System (RBES) and Case-Based Reasoning (CBR), is proposed to facilitate product and process development. Although RBES is adopted for sorting product design criteria, relevant past cases are retrieved by the CBR system during product and process design stages. In doing so, previous knowledge in terms of rules and past practices will be made use of during the product and process design stages, resulting in an enhancement of the efficiency of design and operations. By applying GPDS in Hasbro Fast East Limited, the new product design life cycle is greatly shortened with significant reduction in the total development cost.

Polarization ray tracing, which consist of several extensions to geometrical ray tracing, calculates the evolution of polarization states along ray paths and determines the intrinsic polarization properties, such as diattenuation and retardance, associated with ray paths. This paper compares the suitability of the Jones, Mueller, and a three-dimensional polarization ray tracing calculi, examining the issues of local versus global coordinates, amplitude versus phase representations, inclusion of the wavefront aberration function, partially polarized light, measurements of images by polarimeters, and diffraction image formation by low and high numerical aperture beams.

PurposeSupplier involvement in cost reduction efforts has been concentrated mainly in the product development phase of the life cycle of the product. Often this concentration on the early phases of the product life cycle is defended with referral to the 80/20 rule that says that 80 per cent of the manufacturing costs are determined or committed during product design and development. The purpose of this paper is to look for empirical evidence that supports this rule and discuss the limited literature on joint buyer/supplier cost reduction programmes beyond the product development stage of the product life cycle.Design/methodology/approachAn extensive literature survey on both the cost commitment rule and collaborative cost reduction programmes beyond the product development stage was conducted.FindingsIt was found that empirical evidence in the literature for the 80/20 rule on cost commitment in product design is only anecdotal. Even more surprisingly, compared to the literature on cost reduction in design phases, the literature on cost reduction efforts in later stages of the product life cycle is rather limited and usually ignores possibilities for supplier/buyer collaboration.Research limitations/implicationsFurther empirical research (suggestions provided) should assess whether the identified lack of evidence is due to a gap in the empirical literature or to lower degrees of cost commitment and attention to cost efforts beyond product design indeed existing in practice.Practical implicationsThis paper calls practitioners to revisit the cost commitment rule and check its existence in their specific contexts. As a result of this exercise, practitioners may want to consider implementing some of the techniques reviewed in the paper that can assist in collaborative cost reduction beyond the product development stage.Originality/valueGiven the amount of money involved, the general applicability of the cost reduction techniques to various industries and relationships with suppliers, the opportunities for huge savings and the fact that most firms usually have many products and/or technologies at maturity stage, my research makes an important contribution by identifying both a lack of empirical evidence in the literature on the notion that 80 per cent of the costs are committed in the design phase and the limited attention given in the literature to supplier/buyer cost reduction programmes in further stages of the product life cycle.

Ray tracing is a method that allows the creation of stunning photo‐realistic images on a computer. Most ray tracing programs can model any three‐dimensional object which can be described by mathematical formulae. Looking closely at ray tracing many situations can be found where this technique can be useful. In this article a widely available shareware ray tracing program, PovRay, is described. Some ideas how PovRay can be used in teaching and 3D geometry, physics, and other high school and university subjects.

Virtual prototyping practice and technologies are developing fast and moving from the traditional industrial sectors that have pushed their development (automotive, aeronautical) to new sectors, like the fashion sector, that is far from them, but anyway economically important. The concept of Virtual Prototyping has been built upon a bottom up approach. Tools oriented to different phases of the product development process (CAD, CAM, CAE, etc.) have been developed separately, without any intersection or anything in common among them, except for the idea that the geometrical model of the object is the reference point for the all phases. Actually, each of these tools simulates a single aspect/characteristic of the future product: the shape, the appearance, the manufacturability, the strain, the physical behaviour, etc. On top of them, Virtual Prototyping was developed with multiple aims. First, it aimed at integrating into a unique “object” all the characteristics that are uniquely formalised, and that can be uniquely simulated, so allowing an integration of all the interrelations among the all product aspects. Another characteristic of Virtual Prototyping concerns its use in validation. This has raised the need to make compatible the context where the prototype can or could be virtually operating, in terms of digital modelling. Therefore, the Virtual Prototype can be seen as a correlated set of dedicated models able to simulate specific aspects and models of interaction modalities. The paper presents the key aspects of Virtual Prototyping and enabling technologies in the fashion sector, presenting their benefits and the shortcomings that still require research and development.

Based on the theory of user needs and the product development mode and framework of mobile Internet interactive innovation, a new “reality → virtual → reality” interactive innovation product development mode is constructed. It draws on the unique characteristics, systematic technical system, and comprehensive scientific and technological layout of the Metaverse. On this basis, a framework for product development and design based on interactive innovation from the Metaverse perspective is innovatively proposed. In the Metaverse scenario, interactive innovation knowledge can be easily and effectively transformed into design knowledge, and all groups of users truly participate in the whole process of product design. Moreover, the development of interactive innovative products in the Metaverse scenario can be combined with artificial intelligence (AI) technology to further automate the statistical analysis of user needs and preferences so as to meet the dynamic needs of users and accurately develop products that fit user needs and enterprise standards. In addition, users, designers, and enterprises can make joint decisions on product design solutions and development forms, and the Metaverse technology can also optimize the products with continuous iteration and obtain the optimal solutions. An automotive case study illustrates the feasibility and effectiveness of the model for product development innovation and enterprise digital transformation.

Technology is a major driver for leveraging the potential of multidimensional sustainable development, regardless of the sector examined. Therefore, engineers have an important contribution in developing innovative technical solutions to ensure more sustainable alternatives to conventional processes or products. In order to support this comprehension from an early age on, it is the task of lecturers at universities by developing students access to sustainable engineering activities with new teaching programs. Regarding conventional product development, the question arises how sustainable products can be developed, which concepts for design and which methods for validation and quantification can be used. These and further questions are the basis of the project-based learning (PBL) approach introduced in this paper as part of a new module "Development of Sustainable Products" at the Faculty of Mechanical Engineering at the Leibniz University Hannover. In this paper, the need for new courses in the ecological sustainability context and the requirements for student project work are presented. The concept of the project and the overall objective, that the students are required to assess the ecological environmental impact of electric toothbrushes over the entire product life cycle based on a life cycle assessment (LCA) is introduced. After successfully participating in this project, students are able to conduct ecological sustainability analyses and understand the complexity within the development of sustainable products.

Site-specific ultrawideband propagation modeling involves dealing with frequency variations of the propagation mechanisms and antenna patterns in the ray tracing program. Typically, electromagnetic field calculations have to be performed in a lot of frequencies to accurately construct the frequency response of the channel at a receiving point. This imposes a heavy computational burden on ray tracing specially in calculating the coverage map or finding the statistics of channel parameters where the number of receiving locations is large. In this paper, the computational complexity of ray tracing in ultrawideband propagation modeling is reduced by using cubic B-spline interpolation. The frequency response of the channel at each receiving point is obtained by calculating the electromagnetic fields at a limited number of frequencies and then interpolating the results using cubic B-splines. A speedup of about four times in simulating a typical residential environment is achieved. Besides, the accuracy of the results is maintained due to excellent characteristics of the cubic B-spline interpolation.

The relationship between system theory and the product design, the process of product development has been described. It compared the merits and demerits of serial and parallel product development processes and, with the guidelines of system theory, put forward and analyzed the planning actions and corresponding necessity existed in the indistinct initial phase in product development process. It also analyzed the optimizing effect of planning actions in product design & development process. Thus, it obtained the model of product design & development process based on system theory so as to clarify the indistinct initial phase, shorten product development time and, improve the effectiveness of enterprise's product development.

Interactive rendering requires rapid visual feedback. The render cache is a new method for achieving this when using high-quality pixel-oriented renderers such as ray tracing that are usually considered too slow for interactive use. The render cache provides visual feedback at a rate faster than the renderer can generate complete frames, at the cost of producing approximate images during camera and object motion. The method works both by caching previous results and reprojecting them to estimate the current image and by directing the renderer's sampling to more rapidly improve subsequent images. Our implementation demonstrates an interactive application working with both ray tracing and path tracing renderers in situations where they would normally be considered too expensive. Moreover we accomplish this using a software only implementation without the use of 3D graphics hardware.

The act of performing a sequential trigonometric ray trace through an optical system is as simple as applying Snell's Laws of refraction and reflection, along with some form of the grating equation, to the geometric description of the lenses and mirrors which can comprise that system. The orderly incorporation of these physical laws into an algorithm, which at the same time incorporates all possible geometries which may occur in this optical system, will be the result of this paper. The ray/surface equations and other useful numerical techniques will be spelled out in detail so that this paper can be used as a starting point for their own ray tracing program when commercial optical design codes are either not available or inappropriate.

Three-dimensional concurrent engineering (3DCE) concept provides a new approach for integrating product, process, and supply chain design. The opportunities to shorten product development lead time and time to market eventually, increase product variant and quality, and reduce product development costs become a concern. However, the 3DCE approach is not yet comprehensive since the researches are continuing and growing. This article provides a bibliometric literature review on 3DCE as a term and concept through mainly Scopus database and Mendeley software for managing and resuming the references. After manual filtering and reading we conclude 39 articles strongly related to the term of 3DCE. Finally, we classified the articles based on its keywords into two clusters of words using VOSviewer software. Moreover, we found that ‘supply chain’, ‘product development’, and ‘product design’ were the most frequently used for keywords, titles, or abstracts that represented the research stream or the researcher’s background.