Abstract

Terrains are challenging geometric objects for real-timerendering and interactive manipulation. State-of-the-artterrain rendering systems use custom, multiresolution, rep-resentations like geometry clipmaps for fast rendering onthe GPU. In this paper, we present a system that exploitsthe power and flexibility of the modern GPUs to store, ren-der, and manipulate terrains with minimal CPU involve-ment. The central idea is to use a regular-grid represen-tation and fixed size blocks/tiles that change in resolution.The potentially visible portion of the terrain is cached atthe highest necessary resolution and is rendered from theGPU. The CPU sends a light geometry template which isexpanded by the Geometry Shader to the triangles, usingthe heights stored in the GPU Cache. The CPU performsa coarse culling of the tiles with the GPU performing fineculling. The GPU cache is updated continuously as theviewpoint changes. Our system enables the terrain to bemodified procedurally or edited interactively on the GPUwith no CPU involvement. The terrain can also interactwith a large number of external objects in real-time entirelywithin the GPU. We achieve a consistent rendering rate of100 frames per second with terrain modification and inter-actions as well as a triangle rate of upto 350 million persecond on an Nvidia 8800 GTX GPU for large terrains, witha CPU load below 10%.

Abstract

The GPUs pack high computation power and a restricted architecture into easily available hardware today. They are now used as computation co-processors and come with programming models that treat them as standard paral-lel architectures. We explore the problem of real time raycasting of large deformable models (over a million trian-gles) on large displays (a million pixels) on an off-the-shelf GPU in this paper. Ray casting is an inherently parallel and highly compute intensive operation. We build a GPU-efficient three-dimensional data structure for this purpose and a corresponding algorithm that uses it for fast ray cast-ing. We also present fast methods to build the data struc-ture on the SIMD GPUs, including a fast multi-split opera-tion. We achieve real-time ray-casting of a million triangle model onto a million pixels on current Nvidia GPUs using the CUDA model. Results are presented on the data struc-ture building and ray casting on a number of models. The ideas presented here are likely to extend to later models and architectures of the GPU as well as to other multi core ar-chitectures.

Abstract

The primitives of point-based representations are in-dependent but are rendered using surfels, which approxi-mate the immediate neighborhood of each point linearly.A large number of surfels are needed to convey the exactshape. Higher-order approximations of the local neigh-borhood have the potential to represent the shape usingfewer primitives,simultaneously achieving higher renderingspeeds. In this paper, we proposealgebraic splatsas abasic primitive of representation for point based models.An algebraic splat based representation can be computedusing a moving least squares procedure. We specificallystudy low order polynomial splats in this paper. Quadraticand cubic splats provide good quality and high renderingspeed using far fewer primitives on a wide range of mod-els. They can also be rendered fast using ray tracing onmodern GPUs. We also present an algorithm to constructa representation of a model with a user-specified number ofprimitives. Our method to generates a hole-free represen-tation parametrized by a smoothing radius. The hole-freerepresentation reduces the number of primitives needed bya factor 20 to 30 on most models and by a factor of over100 on dense models like David with little or no drop invisual quality. We also present a two-pass GPU algorithmthat ray-traces the algebraic splats and blends them usinga Gaussian weighting scheme for smooth appearance. Weare able to render models like David at upwards of 200 fpson a commodity GPU using algebraic splats.

Abstract

We present a non-photo realistic, real-time painterly ren-dering technique for terrains. The painterly appearanceand the impression of terrains is created by effectively ren-dering several brush strokes. The strokes have fixed loca-tions on the surfaces of the terrain during animation to en-able frame to frame coherency. The strokes are rendered asalpha blended sprites in two-dimensions and are orientedalong the slope of terrain analogous to the way artists painton canvas. By exploiting the regular nature of terrain data,we create pre-decided rendering depth orders for primitivesfor any camera orientation.With this, we avoid the neces-sity of sorting the primitives of sprites required for alphablending. We use DirectX10/SM4.0 based shaders to renderstrokes to improve performance. Being distributed on ter-rain, strokes get cluttered when they are closely located onscreen. We follow a level of detail scheme that maintains auniform stroke density in screen space. Various styles canbe achieved with different stroke variations. Phong shadingthe rendered output in real-time is possible for more variedstyles. We achieve painterly rendering in real-time with acombination of object space positioning and image spacerendering of strokes. We illustrate our method with imagesand performance results.

Abstract

Indian software industry has set up huge growth targets for future. These targets would be heavily affected by the software engineering (SE) education scenario in the country. The purpose of this paper is to provide a holistic understanding of SE education issues and challenges specific to Indian context, from both industry and academic perspective. This study is based on our (a) interaction with industry through SE education related projects, surveys and discussions. (B) Observations as an integral part of Indian SE educators' community. There is an urgent need for addressing these deep rooted issues, as the lack of proper SE education may be the single largest factor that may negatively affect the industry. Understanding these issues will help to identify the action items that initiate software engineering educational reforms in the country. We also discuss the essential and minimal set of SE knowledge, skills and dispositions that the industry expects from engineers willing to join the industry. Though Indian software industry is growing at phenomenal rates, there not many studies on the issues and effects associated with SE education in the Indian context. Though the discussion is limited to India, but we believe that it represents the existing conditions in many developing countries where IT and ITES (IT Enabled Services) industry is becoming important.

Abstract

Software Engineering (SE) and Information Technology (IT) jobs are the most sought after career options for Indian youth in the recent times. Indian Software industry is expected to grow at a very healthy rate and each major software company has ambitious plans and growth targets for future. However, lack of proper Software Engineering (SE) education may have severe consequences and may negatively affect these growth targets. In this paper we discuss challenges and issues related to software engineering education and training in Indian academia and industry. These are based on our interaction with industry and through our experience as Software engineering educators. These challenges arise from deep rooted issues in Software Engineering educational goals, pedagogy and instruction as well as the infrastructure. We will discuss their long term effects on various aspects of software development. We put forth our suggestions that may handle these challenges to an extent. We also discuss the essential and minimal set of software engineering knowledge, skills and dispositions that the industry requires from young engineers willing to join the industry. This paper provides course designing guidelines for the academia and learning centers of the industry by focusing on important SE education issues, their causes and possible solutions. This, in turn would help to make SE Education more effective and inline with requirements of the Indian Software industry.

Abstract

It is observed that information technology (IT) is being used to automate the traditional government processes and to achieve easy access of the information. They are developed to increase the efficiency of the government departments and represent their needs. As a result, they achieved a huge inventory of IT applications providing disparate processes implemented using different technologies and platforms. It thus became very important to use IT as an" integrator" allowing disparate processes running in different departments to interconnect. This helps the citizen to access different government services through a common single-point window and helps the government to transform from government-centric organization to citizen-centric organization

Abstract

In this paper we present a statistical transliteration technique that is language independent. This technique uses Hidden Markov Model (HMM) alignment and Conditional Random Fields (CRF), a discriminative model. HMM alignment maximizes the probability of the observed (source, target) word pairs using the expectation maximization algorithm and then the character level alignments (n-gram) are set to maximum posterior predictions of the model. CRF has efficient training and decoding processes which is conditioned on both source and target languages and produces globally optimal solutions. We apply this technique for Hindi-English transliteration task. The results show that our technique perfoms better than the existing transliteration system which uses HMM alignment and conditional probabilities derived from counting the alignments.

Abstract

Graphs can be used for effective representation of images for recognition and retrieval purposes. The problem is often to find a proper structure that can efficiently describe an image and can be matched in reasonably low computational expense. The standard solutions to the graph matching problem are computationally expensive since the search space involves all permutations of the nodesets. We compare two graphical representations called the Nearest-Neighbor Graphs and the Collocation Trees, for the goodness of fit and the computational expense involved in matching. Various schemes to index the graphical structures have also been discussed.

Abstract

This paper presents the experiments of Language Technologies Research Centre (LTRC) as part of their participation in CLEF2 2007 Indian language to English ad-hoc cross language document retrieval task. In this paper we discuss our Hindi and Telugu to English CLIR system and the experiments using CLEF 2007 dataset. We used a variant of TFIDF algorithm in combination with a bilingual lexicon for query translation. We also explored the role of a document summary in fielded queries and two different boolean formulations of query translations. We find that a hybrid boolean formulation using a combination of boolean AND and boolean OR operators improves ranking of documents. We also find that simple disjunctive combination of translated query keywords results in maximum recall.