We present a novel approach using rasterization hardware to perform the following query: Given a collection of convex polytopes in 3D, find the closest point from some given point inside the polytopes to the surface of the union of the polytopes. The algorithm takes advantage of multipass rendering, clipping, and depth tests. We also demonstrate its application to penetration depth computation.

We present an approach for computing generalized proximity information between arbitrary polygonal models using graphics hardware acceleration. Our algorithm combines object-space localization, multi-pass rendering techniques, and accelerated distance field computation to perform complex proximity queries at interactive rates. It is applicable to any closed, possibly non-convex, polygonal object and requires no precomputation, making it suitable for both rigid and dynamically deformable geometry of relatively high complexity. The proximity queries include, not only collision detection, but also the computation of intersections, minimum separation distance, closest points, penetration depth and direction, and contact points and normals. The load is balanced between CPU and graphics subsystems through a hybrid geometry and image-based approach. Geometric object-space techniques coarsely localize potential interactions between two objects, and image-space techniques accelerated with graphics hardware provide the low-level proximity information. We have implemented our system using the OpenGL graphics library and have tested it on various hardware configurations with a wide range of object complexities and contact scenarios. In all cases, interactive frame rates are achieved. In addition, our algorithm’s performance is heavily based on the graphics hardware computational power growth curve which has exceeded the expectations of Moore’s Law for general CPU power growth.

Article Fast and simple 2D geometric proximity queries using graphics hardware Share on Authors: Kenneth E. Hoff Univ. of North Carolina, Chapel Hill Univ. of North Carolina, Chapel HillView Profile , Andrew Zaferakis Univ. of North Carolina, Chapel Hill Univ. of North Carolina, Chapel HillView Profile , Ming Lin Univ. of North Carolina, Chapel Hill Univ. of North Carolina, Chapel HillView Profile , Dinesh Manocha Univ. of North Carolina, Chapel Hill Univ. of North Carolina, Chapel HillView Profile Authors Info & Claims I3D '01: Proceedings of the 2001 symposium on Interactive 3D graphicsMarch 2001 Pages 145–148https://doi.org/10.1145/364338.364383Online:01 March 2001Publication History 72citation976DownloadsMetricsTotal Citations72Total Downloads976Last 12 Months14Last 6 weeks0 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteGet Access

Probabilistic roadmap methods have recently received considerable attention as a practical approach for motion planning in complex environments. These algorithms sample a number of con gurations in the free space and build a roadmap. Their performance varies as a function of the sampling strategies and relative con gurations of the obstacles. To improve the performance when the path of a robot has to pass through narrow passages, some researchers have proposed algorithms for sampling along or near the medial axis of the free space. However, their usage has been limited because of the practical complexity of computing the medial axis or the cost of computing such samples. In this paper, we present e cient algorithms for sampling near the medial axis and building roadmap graphs for a freeying rigid body. We use a recent algorithm for fast computation of discrete generalized Voronoi diagrams using graphics hardware [HCK99a]. We initially compute a bounded error discretized Voronoi diagram of the obstacles in the workspace and use it to generate samples in the free space. We use multi-level connection strategies and local planning algorithms to generate roadmap graphs. We also utilize the distance information provided by our Voronoi algorithm for fast proximity queries and sampling the con gurations. The resulting planner has been applied to a number of free ying rigid bodies in 2D (with 3-dof) and 3D (with 6-dof) and compared with the performance of earlier planners using a uniform sampling of the con guration space. Its performance varies with di erent environments and we obtain 25% to over 1000% speed-up.

We present techniques for fast motion planning by using discrete approximations of generalized Voronoi diagrams, computed with graphics hardware. Approaches based on this diagram computation are applicable to both static and dynamic environments of fairly high complexity. We compute a discrete Voronoi diagram by rendering a 3D distance mesh for each Voronoi site. The sites can be points, line segments, polygons, polyhedra, curves and surfaces. The computation of the generalized Voronoi diagram provides fast proximity query toolkits for motion planning. The tools provide the distance to the nearest obstacle stored in the Z-buffer, as well as the Voronoi boundaries, Voronoi vertices and weighted Voronoi graphs extracted from the frame buffer using continuation methods. We have implemented these algorithms and demonstrated their performance for path planning in a complex dynamic environment composed of more than 140,000 polygons.

We present a system for rendering very complex 3D models at interactive rates. We select a subset of the model as preferred viewpoints and partition the space into virtual cells. Each cell contains near geometry, rendered using levels of detail and visibility culling, and far geometry, rendered as a textured depth mesh. Our system automatically balances the screen-space errors resulting from geometric simplification with those from textureddepth-mesh distortion. We describe our prefetching and data management schemes, both crucial for models significantly larger than available system memory. We have successfully used our system to accelerate walkthroughs of a 13 million triangle model of a large coal-fired power plant and of a 1.7 million triangle architectural model. We demonstrate the walkthrough of a 1.3 GB power plant model with a 140 MB cache footprint.

This paper presents a new method for interactive rendering of globally illuminated static scenes. Global illumination is decomposed into view-independent (diffuse) and view-dependent (non-diffuse) components. The two are recombined during rendering using a hybrid geometryand image-based approach along with multi-pass blending techniques. This approach allows the preprocessing of both components and the fast rendering of globally illuminated scenes. The view-independent component uses a traditional precomputed geometry-based radiosity solution that is rendered using standard graphics hardware. The view-dependent component is decomposed into “what is reflected” (radiance with depth) and “how it is reflected” (BRDF), and precomputed and rendered using image-based approaches. Radiance is stored as images with depth, and rendered using perspective reprojection; the BRDF is decomposed into an integration of incoming radiance and a directional modulation. The radiance integration term is approximated by convolving the reflected image with precomputed kernel textures based on material properties. The directional modulation is stored as a reflectance modulation texture based on material properties and is rendered using spheremapping during a blending pass.

We present a framework for rendering very large 3D models at nearly interactive rates. The framework scales with model size. Our framework can integrate multiple rendering acceleration techniques, including visibility culling, geometric levels of detail, and image-based approaches. We describe the database representation scheme for massive models used by the framework. We provide an effective pipeline to manage the allocation of system resources among different techniques. We demonstrate the system on a model of a coal-fired power plant composed of more than 15 million triangles. CR Categories and Subject Headings: H.2 – Database Management, I.3.3 – Picture/Image Generation (Display Algorithms), I.3.4 – Graphics Utilities (Application packages), I.3.6 – Methodology and Techniques (Graphics data structures), I.3.7 – Three-Dimensional Graphics and Realism (Virtual reality), J.2 – Physical Sciences and Engineering (Engineering), J.6 – Computer-Aided Engineering (Computer-aided design)

Article Free Access Share on Accelerated walkthrough of large spline models Authors: Subodh Kumar Department of Computer Science, Johns Hopkins University, Baltimore, MD Department of Computer Science, Johns Hopkins University, Baltimore, MDView Profile , Dinesh Manocha Department of Computer Science, University of North Carolina, Chapel Hill, NC Department of Computer Science, University of North Carolina, Chapel Hill, NCView Profile , Hansong Zhang Department of Computer Science, University of North Carolina, Chapel Hill, NC Department of Computer Science, University of North Carolina, Chapel Hill, NCView Profile , Kenneth E. Hoff Department of Computer Science, University of North Carolina, Chapel Hill, NC Department of Computer Science, University of North Carolina, Chapel Hill, NCView Profile Authors Info & Claims I3D '97: Proceedings of the 1997 symposium on Interactive 3D graphicsApril 1997 Pages 91–ff.https://doi.org/10.1145/253284.253313Online:30 April 1997Publication History 13citation447DownloadsMetricsTotal Citations13Total Downloads447Last 12 Months1Last 6 weeks1 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteeReaderPDF

The increasing demands of 3D game realism - in terms of both scene complexity and speed of animation - are placing excessive strain on the current low-level, computationally expensive graphics drawing operations. Despite these routines being highly optimized, specialized, and often being implemented in assembly language or even in hardware, the ever-increasing number of drawing requests for a single frame of animation causes even these systems to become overloaded, degrading the overall performance. To offset these demands and dramatically reduce the load on the graphics subsystem, we present a system that quickly and efficiently finds a large portion of the game world that is not visible to the viewer for each frame of animation, and simply prevents it from being sent to the graphics system. We build this searching mechanism for unseen parts from common and easily implemented graphics algorithms.

Many applications in computer graphics and virtual environments need to render datasets with large numbers of primitives and high depth complexity at interactive rates. However, standard techniques like view frustum culling and a hardware z-bu er are unable to display datasets composed of hundred of thousands of polygons at interactive frame rates on current high-end graphics systems. We add a \conservative"visibility culling stage to the rendering pipeline, attempting to identify and avoid processing of occluded polygons. Given a moving viewpoint, the algorithm dynamically chooses a set of occluders. Each occluder is used to compute a shadow frustum, and all primitives contained within this frustumare culled. The algorithmhierarchicallytraverses the model, culling out parts not visible from the current viewpoint using e cient, robust, and in some cases specialized interference detection algorithms. The algorithm's performance varies with the location of the viewpoint and the depth complexity of the model. In the worst case it is linear in the input size with a small constant. In this paper, we demonstrate its performance on a city model composed of 500;000 polygons and possessing varying depth complexity. We are able to cull an average of 55% of the polygons that would not be culled by view-frustum culling and obtain a commensurate improvement in frame rate. The overall approach is e ective and scalable, is applicable to all polygonal models, and can be easily implemented on top of view-frustum culling.

We present hierarchical occlusion maps (HOM) for visibility culling on complex models with high depth complexity. The culling algorithm uses an object space bounding volume hierarchy and a hierarchy of image space occlusion maps. Occlusion maps represent the aggregate of projections of the occluders onto the image plane. For each frame, the algorithm selects a small set of objects from the modelas occludersand renders them to form an initial occlusion map, from which a hierarchy of occlusion maps is built. The occlusion maps are used to cull away a portion of the model not visible from the current viewpoint. The algorithm is applicable to all models and makes no assumptions about the size, shape, or type of occluders. It supports approximate culling in which small holes in or among occluders can be ignored. The algorithm has been implemented on current graphics systems and has been applied to large models composed of hundreds of thousands of polygons. In practice, it achieves significant speedup in interactive walkthroughs of models with high depth complexity. CR

Article Free Access Share on Fast backface culling using normal masks Authors: Hansong Zhang CB #3175, Sitterson Hall, UNC-CH, Chapel Hill, NC and Department of Computer Science, University of North Carolina at Chapel Hill CB #3175, Sitterson Hall, UNC-CH, Chapel Hill, NC and Department of Computer Science, University of North Carolina at Chapel HillView Profile , Kenneth E. Hoff CB #3175, Sitterson Hall, UNC-CH, Chapel Hill, NC and Department of Computer Science, University of North Carolina at Chapel Hill CB #3175, Sitterson Hall, UNC-CH, Chapel Hill, NC and Department of Computer Science, University of North Carolina at Chapel HillView Profile Authors Info & Claims I3D '97: Proceedings of the 1997 symposium on Interactive 3D graphicsApril 1997Pages 103–ff.https://doi.org/10.1145/253284.253314Published:30 April 1997Publication History 37citation462DownloadsMetricsTotal Citations37Total Downloads462Last 12 Months105Last 6 weeks24 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteeReaderPDF