waashk/acm huggingface dataset:
modeling pigmented materials for realistic image synthesis  this article discusses and applies the kubelka-munk theory of pigment mixing to computer graphics in order to facilitate improved image synthesis. the theories of additive and subtractive color mixing are discussed and are shown to be insufficient for pigmented materials. the kubelka--munk theory of pigment mixing is developed and the relevant equations are derived. pigment mixing experiments are performed and the results are displayed on color television monitors. a paint program that uses kubelka--munk theory to mix real pigments is presented. theories of color matching with pigments are extended to determine reflectances for use in realistic image synthesis.  chet s. haase gary w. meyer
topology matching for fully automatic similarity estimation of 3d shapes  there is a growing need to be able to accurately and efficiently search visual data sets, and in particular, 3d shape data sets. this paper proposes a novel technique, called _topology matching_, in which similarity between polyhedral models is quickly, accurately, and automatically calculated by comparing multiresolutional reeb graphs (mrgs). the mrg thus operates well as a search key for 3d shape data sets. in particular, the mrg represents the skeletal and topological structure of a 3d shape at various levels of resolution. the mrg is constructed using a continuous function on the 3d shape, which may preferably be a function of geodesic distance because this function is invariant to translation and rotation and is also robust against changes in connectivities caused by a mesh simplification or subdivision. the similarity calculation between 3d shapes is processed using a coarse-to-fine strategy while preserving the consistency of the graph structures, which results in establishing a correspondence between the parts of objects. the similarity calculation is fast and efficient because it is not necessary to determine the particular pose of a 3d shape, such as a rotation, in advance. topology matching is particularly useful for interactively searching for a 3d object because the results of the search fit human intuition well.  masaki hilaga yoshihisa shinagawa taku kohmura tosiyasu l. kunii
simulation: pushing a dead mouse through a maze?  simulation has been defined in various ways, depending upon the particular biases of the definer. as an example, simulation has been defined, albeit facetiously, as "pushing a dead mouse through a maze". the definition is examined in the paper. special emphasis is given to the recent changes that have occurred in user acceptance and consideration is given to trends in the field. the need for increased accessibility to simulation is the primary focus of the paper.  john a. white
a language-directed distributed discrete simulation system (extended abstract)  in recent years, there has been a noticable increase of interest into the feasibility and utility of distributed discrete simulation. this has been prompted by an improvement in distributed algorithms and distributed computer systems, as well as the need to economically manage the increasingly complex simulation models found in today's world.  researchers have centered their efforts around two distinctly different approaches to the design and implementation of distributed discrete simulation systems, with the differences based on what types of tasks are distributed to the individual processors. the more common approach researchers have taken is to develop a system in which the model functions (events) are distributed among the processors (1, 3, 7, 8). the alternative approach distributes simulation support functions (e.g. random number generation) to the available processors (4,9).  dana l. wyatt sallie sheppard
towards a consistent logical framework for ontological analysis in their framework for ontological analysis, guarino and weltyprovide a number of insights that are useful for guiding the designof taxonomic hierarchies. however, the formal statements of theseinsights as logical schemata are flawed in a number of ways,including inconsistent notation that makes the intended semanticsof the logic unclear, false claims of logical consequence, anddefinitions that provably result in the triviality of some of theirproperty features. this paper makes a negative contribution, bydemonstrating these flaws in a rigorous way, but also makes apositive contribution wherever possible, by identifying theunderlying intuitions that the faulty definitions were intended tocapture, and attempting to formalize those intuitions in a moreaccurate way. aaron n. kaplan
the virtual mesh: a geometric abstraction for efficiently computing radiosity in this article, we introduce a general-purpose method for computing radiosity on scenes made of parametric surfaces with arbitrary trimming curves. in contrast with past approaches that require a tessellation of the input surfaces (be it made up of triangles or patches with simple trimming curves) or some form of geometric approximation, our method takes full advantage of the rich and compact mathematical representation of objects. at its core lies the _virtual mesh_, an abstraction of the input geometry that allows complex shapes to be illuminated as if they were simple primitives. the virtual mesh is a collection of normalized square domains to which the input surfaces are mapped while preserving their energy properties. radiosity values are then computed on these supports before being lifted back to the original surfaces. to demonstrate the power of our method, we describe a high-order wavelet radiosity implementation that uses the virtual mesh. examples of objects and environments, designed for interactive applications or virtual reality, are presented. they prove that, by exactly integrating curved surfaces in the resolution process, the virtual mesh allows complex scenes to be rendered more quickly, more accurately, and much more naturally than with previously known methods. l. alonso f. cuny s. petit jean j.-c. paul s. lazard e. wies
probabilistic logic programming with conditional constraints  we introduce a new approach to probabilistic logic programming in which probabilities are defined over a set of possible worlds. more precisely, classical program clauses are extended by a subinterval of [0,1] that describes a range for the conditional probability of the head of a clause given its body. we then analyze the complexity of selected probabilistic logic programming tasks. it turns out that probabilistic logic programming is computationally more complex than classical logic programming, more precisely, the tractability of special cases of classical logic programming generally does not carry over to the corresponding special cases of probabilistic logic programming. moreover, we also draw a precise picture of the complexity of deciding and computing tight logical consequences in probabilistic reasoning with conditional constraints in general. we then present linear optimization techniques for deciding satisfiability and computing tight logical consequencesof probabilistic logic programs. these techniques are efficient in the special case in which we have little relevant purely probabilistic knowledge. we finally show that probabilistic logic programming under certain syntactic and semantic restrictions is closely related to van emden's quantitative deduction, and thus has computational properties similar to calssical logic programming. based on this result, we present an efficient approximation technique for probabilistic logic programming.  thomas lukasiewicz
the morph node  we discuss potential and limitations of a morph node, inspired by the corresponding construct in java3d. a morph node in java3d interpolates vertex attributes among several homeomorphic geometries. this node is a promising candidate for the delivery of 3d animation in a very compact form. we review the state-of-the-art in web 3d techniques with respect to the possibility of interpolating among several geometries. this review leads to a simple extension for vrml-97 as well as a recommendation for necessary changes in java3d. furthermore, we discuss various optimization issues for morph nodes.  marc alexa johannes behr wolfgang muller
automating the technical publications department  a day at the office \---1995  by the time george denning arrives at his office at seacom, inc., at 10:30 a.m. this morning, he has already done three hours of work. george, a senior technical writer in the software publications department, wanted some isolation this morning to edit a particularly tricky section in a user guide. his home computer, hooked up to seacom's host computer through the local cable network, allowed him to edit the document on- line in the quiet of his den, browse through his company mailbox, and glance at the latest changes to a functional specification fred herbert has been working on. although fred is the analyst in charge of project development, george is responsible for all ergonomic considerations. wishing to avoid the chit-chat of a telephone call, george linked up with fred and the user liason on the project for a three-way computer conference. in five minutes george had explained the problem he had found, and, with the three looking at the specifications on-line, had changed it to everyone's satisfaction. finished, george logged off of seacom and left for the office.  arriving at seacom, george gets a cup of tea and turns on his terminal. the system alerts him that a document has been returned from review. although the committee members are scattered around the country, it has only taken five days for the entire review cycle. all of the comments have been made on-line. george calls up the review copy on his terminal. the text of the document is formatted on the screen, and blinking red arrows scattered throughout the document show where comments were made. george issues a command, and the document compresses onto the left-hand half of the screen, while the comments appear on the right-hand half. in an hour he has made the changes and sent the file off to the certification board for approval.  reviewing the document he edited at home in the morning, george decides an illustration is called for. he queries the corporate graphics library on-line for similar illustrations. the description of one sounds promising. calling it up on the screen, he decides that, with a few changes, it will fill the bill. rapidly he draws a few more lines and connectors, adds a photo of a particular device (copied from the corporate photo archives in digital form) and incorporates it into his document as a figure. the system instantly boxes and labels it, and updates the list of figures in the table of contents.  john d. browne
a concurrent on-board vision system for a mobile robot  robot vision algorithms have been implemented on an 8-node ncube-at hypercube system onboard a mobile robot (hermies) developed at oak ridge national laboratory. images are digitized using a framegrabber mounted in a vme rack. image processing and analysis are performed on the hypercube system. the vision system is integrated with robot navigation and control software, enabling the robot to find the front of a mockup control panel, move up to the panel, and read an analog meter. among the concurrent algorithms used for image analysis are a new component labeling algorithm and a hough transform algorithm with load balancing.  j. p. jones
drawing antialiased cubic spline curves  cubic spline curves have many nice properties that make them desirable for use in comptuer graphics, and the advantages of antialiasing have been known for some years. yet, only recently has there been any attempt at directly antialiasing spline curves. parametric spline curves have resisted antialiasing in several ways: single segments may cross or become tangent to themselves. cusps and small loops are easily missed entirely. thus, short pieces of the curve cannot necessarily be rendered in isolation. finding the distance from a pixel center to the curve accurately and efficiently---usually an essential part of antialiasing---is an unsolved problem. the method presented by lien, shantz, and pratt [21] is a good start, although it considers pixel-length pieces of the curve in isolation and lacks robustness in the handling of certain curves. this paper provides an improved method that is more robust, and is able to handle intersections and tangency.  r. victor klassen
a multi-agent reinforcement learning method for a partially-observable competitive game  this article proposes a reinforcement learning (rl) method based on an actor- critic architecture, which can be applied to partially-observable multi-agent competitive games. as an example, we deal with a card game "hearts". in our method, the actor plays so as to enlarge the expected temporal-difference error, which is obtained based on the estimation of the state transition. the state transition is estimated by taking the inferred card distribution and the other player's action models into account.  yoichiro matsuno tatsuya ymazaki shin ishii jun matsuno
predicting the future: resource requirements and predictive optimism  the partitioning of systems for parallel simulation is a complex task, requiring consideration of both computational load requirements and communications activity. typically, this information is not accurately known prior to execution. this paper investigates the use of historical information for the prediction of future requirements, both for computation and communications. in addition, for optimistic simulation algorithms, we present a novel technique (which we call predictive optimism) whereby binary prediction schemes can be used to increase the accuracy of optimistic assumptions, thereby decreasing rollbacks and potentially improving overall simulator performance.  bradley l. noble roger d. chamberlain
interpreting statutory predicates  in this paper we discuss a hybrid approach to the problem of statutory interpretation that involves combining our past approach to case-based reasoning ("cba"), as exemplified in our previous hypo and tax-hypo systems, with traditional rule-based reasoning ("rbr"), as exemplified by expert systems. we do not tackle the fullblown version of statutory interpretation, which would include reasoning with legislative intent or other normative aspects (the "ought"), but confine ourselves to reasoning with explicit cases and rules. we discuss strategies that can be used to guide interpretation, particularly the interleaving of cbr and rbr, and how they are used in an agenda-based architecture, called cabaret, which we are currently developing in a general way and experimenting with in the particular area of section 280a(c)(1) of the u.s. internal revenue code, which deals with the so called "home office deduction".  e. l. rissland d. b. skalak
face fixer: compressing polygon meshes with properties  most schemes to compress the topology of a surface mesh have been developed for the lowest common denominator: triangulated meshes. we propose a scheme that handles the topology of arbitrary polygon meshes. it encodes meshes directly in their polygonal representation and extends to capture face groupings in a natural way. avoiding the triangulation step we reduce the storage costs for typical polygon models that have group structures and property data.  martin isenburg jack snoeyink
a microfacet-based brdf generator  a method is presented that takes as an input a 2d microfacet orientation distribution and produces a 4d bidirectional reflectance distribution function (brdf). this method differs from previous microfacet-based brdf models in that it uses a simple shadowing term which allows it to handle very general microfacet distributions while maintaining reciprocity and energy conservation. the generator is shown on a variety of material types.  michael ashikmin simon premoze peter shirley
interactive pen-and-ink illustration  we present an interactive system for creating pen-and-ink illustrations. the system uses stroke textures\\---collections of strokes arranged in different patterns---to generate texture and tone. the user "paints" with a desired stroke texture to achieve a desired tone, and the computer draws all of the individual strokes.  the system includes support for using scanned or rendered images for reference to provide the user with guides for outline and tone. by following these guides closely, the illustration system can be used for interactive digital halftoning, in which stroke textures are applied to convey details that would otherwise be lost in this black-and-white medium.  by removing the burden of placing individual strokes from the user, the illustration system makes it possible to create fine stroke work with a purely mouse-based interface. thus, this approach holds promise for bringing high- quality black-and-white illustration to the world of personal computing and desktop publishing.  michael p. salisbury sean e. anderson ronen barzel david h. salesin
multiresolution techniques for interactive texture-based volume visualization  we present a multiresolution technique for interactive texture-based volume visualization of very large data sets. this method uses an adaptive scheme that renders the volume in a region-of-interest at a high resolution and the volume away from this region at progressively lower resolutions. the algorithm is based on the segmentation of texture space into an octree, where the leaves of the tree define the original data and the internal nodes define lower- resolution versions. rendering is done adaptively by selecting high- resolution cells close to a center of attention and low-resolution cells away from this area. we limit the artifacts introduced by this method by modifying the transfer functions in the lower-resolution data sets and utilizing spherical shells as a proxy geometry. it is possible to use this technique to produce viewpoint-dependent renderings of very large data sets.  eric lamar bernd hamann kenneth i. joy
gpss - finding the appropriate world-view  every simulation language embodies a world-view which heavily influences approaches taken in building models in the language. in most applications for which a given language is used, the world-view of the language enforces a discipline of programming which results in models which are time- and space- efficient, reflecting the usefulness of the language and the appropriateness of language choice by the programmer. for some applications, however, the programming style encouraged by the world-view of a language can lead to programs which are time- and space-inefficient, even though the programs are natural, straightforward solutions to the problem at hand. in such cases, one may be forced to consider alternative languages or to alter one's approach in application of a given language. this paper briefly summarizes the world-view of the gpss language and gives two examples of systems which, when modelled with conventional gpss approaches, result in inefficient programs. for each system, two gpss models are presented: a straightforward model which is inefficient, and a clever model which is efficient. in both cases, the clever models are easily programmed in gpss and require only marginally more skill on the part of the programmer than do the straightforward models. once an appropriate alternative to the obvious gpss world-view is found, the rest is easy. a working knowledge of gpss is required to read this paper.  james o. henriksen
development of a blackboard system for robot programming  this paper describes the development of a blackboard system for robot programming. the blackboard architecture is a system architecture which provides a structured way of coordinating different sub-systems in such a way that they can work together to solve problems. a blackboard system was implemented in prolog and it has been applied successfully for the automatic generation of control code for a robot to perform the task of block assembly in an environment with an obstacle. in this blackboard system, the user- interface to the system is treated as an additional knowledge source of the system. through this knowledge source, the user can find out the status of the operation. he can also modify the goal specifications and the robot will plan according to the new specification.  grantham k. h. pang
caricatures from images  a caricature is a graphical coding of facial features that seeks, paradoxically, to be more like the face than the face itself. a theory of computation for caricatures of frontal faces has been developed and implemented in computer graphics. the caricature generator starts with a digitized image of a face and distorts a line drawing representation of the face relative to a norm. this transformation emphasizes perceptually significant information, reduces noise, and exploits some of the same mechanisms used in human memory for faces.  susan e. brennan
fast volumetric deformation on general purpose hardware  high performance deformation of volumetric objects is a common problem in computer graphics that has not yet been handled sufficiently. as a supplement to 3d texture based volume rendering, a novel approach is presented, which adaptively subdivides the volume into piecewise linear patches. an appropriate mathematical model based on tri-linear interpolation and its approximations is proposed. new optimizations are introduced in this paper which are especially tailored to an efficient implementation using general purpose rasterization hardware, including new technologies, such as vertex programs and pixel shaders. additionally, a high performance model for local illumination calculation is introduced, which meets the aesthetic requirements of visual arts and entertainment. the results demonstrate the significant performance benefit and allow for time-critical applications, such as computer assisted surgery.  c. rezk-salama m. scheuering g. soza g. greiner
iris performer: a high performance multiprocessing toolkit for real-time 3d graphics  this paper describes the design and implementation of iris performer, a toolkit for visual simulation, virtual reality, and other real- time 3d graphics applications. the principal design goal is to allow application developers to more easily obtain maximal performance from 3d graphics workstations which feature multiple cpus and support an immediate- mode rendering library. to this end, the toolkit combines a low-level library for high-performance rendering with a high-level library that implements pipelined, parallel traversals of a hierarchical scene graph. while discussing the toolkit architecture, the paper illuminates and addresses performance issues fundamental to immediate-mode graphics and coarse-grained, pipelined multiprocessing. graphics optimizations focus on efficient data transfer to the graphics subsystem, reduction of mode settings, and restricting state inheritance. the toolkit's multiprocessing features solve the problems of how to partition work among multiple processes, how to synchronize these processes, and how to manage data in a pipelined, multiprocessing environment. the paper also discusses support for intersection detection, fixed-frame rates, run-time profiling and special effects such as geometric morphing.  john rohlf james helman
two implementations of a concurrent simulation environment  this paper discusses the design of a concurrent simulation environment hosted on the ada programming language at the laboratory for software research at texas a & m university. this environment was first implemented on a vax 11/750 single processor system and then ported to a sequent balance 8000 parallel computer system with ten processors. two run-time ada systems were available on the sequent: one for sequential and one for parallel. this paper reports our experiences in porting the original software to these new environments.  carolyn hughes usha chandra sallie v. sheppard