Distributed ray tracing algorithms are widely used when rendering massive scenes, where data utilization and load balancing are the keys to improving performance. One essential observation is that rays are temporally ...
详细信息
Distributed ray tracing algorithms are widely used when rendering massive scenes, where data utilization and load balancing are the keys to improving performance. One essential observation is that rays are temporally coherent, which indicates that temporal information can be used to improve computational efficiency. In this paper, we use temporal coherence to optimize the performance of distributed ray tracing. First, we propose a temporal coherence-based scheduling algorithm to guide the task/data assignment and scheduling. Then, we propose a virtual portal structure to predict the radiance of rays based on the previous frame, and send the rays with low radiance to a precomputed simplified model for further tracing, which can dramatically reduce the traversal complexity and the overhead of network data transmission. The approach was validated on scenes of sizes up to 355 GB. Our algorithm can achieve a speedup of up to 81% compared to previous algorithms, with a very small mean squared error.
Since the shape of a soft object changes in response to its surroundings, it is difficult to give a single position in space as the location of the object. Indeed objects can and do break dynamically into subobjects. ...
详细信息
Since the shape of a soft object changes in response to its surroundings, it is difficult to give a single position in space as the location of the object. Indeed objects can and do break dynamically into subobjects. This means that you cannot map a solid texture onto such an object simply by using a function of the space coordinates. We have taken a different approach. Our soft objects are modeled as the volume enclosed by an isosurf ace of a field calculated from a set of key points. For each key point, we describe an abstract texture space. Any point on the surface of an object has, associated with each key point, a position in this space and a field contribution. A vector sum of these positions, weighted by the field contributions, is used to select a surface specification from the texture space. Textures mapped with this process retain their consistency during distortion and metamorphoses of objects, permitting a great variety of animation effects.
Interactive 3D terrain visualization plays an important role in multiple networked applications like virtual worlds visualization, multiplayer games or distributed simulators. Since the client/server architecture has ...
详细信息
Interactive 3D terrain visualization plays an important role in multiple networked applications like virtual worlds visualization, multiplayer games or distributed simulators. Since the client/server architecture has obvious scalability limitations, different peer-to-peer schemes have been proposed as trade-off solutions that yield good robustness, availability and scalability for this kind of systems. In this paper, we propose a new hybrid distributed architecture that significantly improves the scalability and performance of the existing proposals. The proposed scheme redesigns the relationships between the different elements of a hybrid architecture, modifies the information shared by each client with its neighboring peers and varies the messages exchanged among them, providing a larger number of users with a fluid navigation experience over a large virtual terrain.
A generalized method is presented for analyzing the fringe patterns frequently encountered in experimental mechanics. By utilizing digital-image-processing and computer-graphics techniques, a set of menu-driven softwa...
详细信息
A generalized method is presented for analyzing the fringe patterns frequently encountered in experimental mechanics. By utilizing digital-image-processing and computer-graphics techniques, a set of menu-driven software is developed for interactively implementing the fringe processing. Tests of this software on the images obtained experimentally by photoelasticity, holographic interferometry and speckle interferometry demonstrate its usefulness. Good agreement between the experimental and theoretical results is established.
Social Snapshot is a system for temporally coupled social photography. It leverages computer graphics and computer vision advances, along with the ubiquity of consumer-level programmable cell phone cameras, to activel...
详细信息
Social Snapshot is a system for temporally coupled social photography. It leverages computer graphics and computer vision advances, along with the ubiquity of consumer-level programmable cell phone cameras, to actively acquire time-varying spatial data. Social Snapshot enables spatiotemporal 3D photography using commodity devices, assisted by their auxiliary sensors and network functionality. The end result is a set of locally optimized 2.5D meshes—one for each input photograph—created with a novel mesh generation technique. Although these models could be globally inconsistent, the navigation model uses the recovered camera-pose information and view interpolation techniques to smoothly navigate the reconstruction interactively.
A proposed rule-based editing metaphor intuitively lets artists create buildings without changing their workflow. It's based on the realization that the rule base represents a directed acyclic graph and on a shift...
详细信息
A proposed rule-based editing metaphor intuitively lets artists create buildings without changing their workflow. It's based on the realization that the rule base represents a directed acyclic graph and on a shift in the development paradigm from product-based to rule-based representations. Users can visually add or edit rules, connect them to control the workflow, and easily create commands that expand the artist's toolbox (for example, Boolean operations or local controlling operators). This approach opens new possibilities, from model verification to model editing through graph rewriting. [ABSTRACT FROM PUBLISHER]
The demand for high quality and speed in graphical representations of 3D scenes is continuously increasing. An important aspect of visual realism is real-time processing of transparent objects. In order to provide a r...
详细信息
The demand for high quality and speed in graphical representations of 3D scenes is continuously increasing. An important aspect of visual realism is real-time processing of transparent objects. In order to provide a realistic solution to be considered for future graphics cards, proposed extensions to the hardware need to be small. In this paper, we propose two new hardware oriented proposals for computing order independent transparency for any number of layers. The first proposal is based on the precomputation of the contribution factor of each element to the final colour of the pixel. This permits the evaluation of the transparent objects without requiring their previous sorting. The second proposal is based on the utilization of a pre-sorting stage so that the transparent objects are organized in a back to front order. In both proposals, time requirements are reduced with respect to previous solutions.
Aiming at robust surface structure recovery, we extend the powerful optimization technique of variational shape approximation by allowing for several different primitives to represent the geometric proxy of a surface ...
详细信息
Aiming at robust surface structure recovery, we extend the powerful optimization technique of variational shape approximation by allowing for several different primitives to represent the geometric proxy of a surface region. While the original paper only considered planes, we also include spheres, cylinders, and more complex rolling-ball blend patches. The motivation for this choice is the fact that most technical CAD objects consist of patches from these four categories. The robust segmentation and global optimization properties which have been observed for the variational shape approximation carry over to our hybrid extension. Hence, we can use our algorithm to segment a given mesh model into characteristic patches and provide a corresponding geometric proxy for each patch. The expected result that we recover surface structures more robustly and thus obtain better approximations with a smaller number of primitives, is validated and demonstrated on a number of examples.
We present a volume rendering algorithm which renders images at approximately two to seven times the speed of a conventional ray easter with almost no visible loss of image quality. This algorithm traverses the volume...
详细信息
We present a volume rendering algorithm which renders images at approximately two to seven times the speed of a conventional ray easter with almost no visible loss of image quality. This algorithm traverses the volume data in object order and renders the image by performing ray casting for the pixels within the footprint of the voxel (i.e., rectangular prism) being processed. The proposed algorithm supports the rendering of both single and multiple isosurfaces with arbitrary opacity values. While the projection approach to volume rendering is not new, we present an algorithm specifically designed for the perspective projection, evaluate its rendering speed for both single and multiple isosurfaces with arbitrary opacity values, and examine how efficiently it uses cache memory.
Large datasets can mean slow queries, for which users must wait. Incremental visualization systems can give faster results at a cost of accuracy. This article asked analysts to use one and report on their results. The...
详细信息
Large datasets can mean slow queries, for which users must wait. Incremental visualization systems can give faster results at a cost of accuracy. This article asked analysts to use one and report on their results. Their feedback provides suggestions for alternative visualizations to represent a query still in progress.
暂无评论