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102
High-Quality Pre-Integrated Volume Rendering Using Hardware-Accelerated Pixel Shading
, 2001
"... We introduce a novel texture-based volume rendering approach that achieves the image quality of the best post-shading approaches with far less slices. It is suitable for new flexible consumer graphics hardware and provides high image quality even for low-resolution volume data and non-linear transfe ..."
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Cited by 246 (22 self)
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We introduce a novel texture-based volume rendering approach that achieves the image quality of the best post-shading approaches with far less slices. It is suitable for new flexible consumer graphics hardware and provides high image quality even for low-resolution volume data and non-linear transfer functions with high frequencies, without the performance overhead caused by rendering additional interpolated slices. This is especially useful for volumetric effects in computer games and professional scientific volume visualization, which heavily depend on memory bandwidth and rasterization power.
Hardware-Based Ray Casting for Tetrahedral Meshes
- In Proc. IEEE Visualization ’03
, 2003
"... Figure 1: All images show tetrahedral meshes consisting of 125K to 190K cells rendered with our hardware-based ray casting algorithm. The algorithm exploits the programmable fragment unit of the ATI Radeon 9700 graphics chip and runs at several frames per second in a 512 × 512 viewport. The left ima ..."
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Cited by 79 (5 self)
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Figure 1: All images show tetrahedral meshes consisting of 125K to 190K cells rendered with our hardware-based ray casting algorithm. The algorithm exploits the programmable fragment unit of the ATI Radeon 9700 graphics chip and runs at several frames per second in a 512 × 512 viewport. The left image shows multiple shaded isosurfaces, the middle and right images are rendered with a full density-emitter model. We present the first implementation of a volume ray casting algorithm for tetrahedral meshes running on off-the-shelf programmable graphics hardware. Our implementation avoids the memory transfer bottleneck of the graphics bus since the complete mesh data is stored in the local memory of the graphics adapter and all computations, in particular ray traversal and ray integration, are performed by the graphics processing unit. Analogously to other ray casting algorithms, our algorithm does not require an expensive cell sorting. Provided that the graphics adapter offers enough texture memory, our implementation performs comparable to the fastest published volume rendering algorithms for unstructured meshes. Our approach works with cyclic and/or non-convex meshes and supports early ray termination. Accurate ray integration is guaranteed by applying pre-integrated volume rendering. In order to achieve almost interactive modifications of transfer functions, we propose a new method for computing three-dimensional preintegration tables.
Hardware-assisted visibility sorting for unstructured volume rendering
- IEEE Transactions on Visualization and Computer Graphics
, 2005
"... Abstract—Harvesting the power of modern graphics hardware to solve the complex problem of real-time rendering of large unstructured meshes is a major research goal in the volume visualization community. While, for regular grids, texture-based techniques are well-suited for current GPUs, the steps ne ..."
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Cited by 54 (11 self)
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Abstract—Harvesting the power of modern graphics hardware to solve the complex problem of real-time rendering of large unstructured meshes is a major research goal in the volume visualization community. While, for regular grids, texture-based techniques are well-suited for current GPUs, the steps necessary for rendering unstructured meshes are not so easily mapped to current hardware. We propose a novel volume rendering technique that simplifies the CPU-based processing and shifts much of the sorting burden to the GPU, where it can be performed more efficiently. Our hardware-assisted visibility sorting algorithm is a hybrid technique that operates in both object-space and image-space. In object-space, the algorithm performs a partial sort of the 3D primitives in preparation for rasterization. The goal of the partial sort is to create a list of primitives that generate fragments in nearly sorted order. In image-space, the fragment stream is incrementally sorted using a fixed-depth sorting network. In our algorithm, the object-space work is performed by the CPU and the fragment-level sorting is done completely on the GPU. A prototype implementation of the algorithm demonstrates that the fragment-level sorting achieves rendering rates of between one and six million tetrahedral cells per second on an ATI Radeon 9800. Index Terms—Volume visualization, graphics processors, visibility sorting. 1
Isosurface Computation Made Simple: Hardware Acceleration, Adaptive Refinement and Tetrahedral Stripping
- In Joint Eurographics - IEEE TVCG Symposium on Visualization (VisSym
, 2004
"... This paper presents a simple approach for rendering isosurfaces of a scalar field. Using the vertex programming capability of commodity graphics cards, we transfer the cost of computing an isosurface from the Central Processing Unit (CPU), running the main application, to the Graphics Processing U ..."
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Cited by 51 (2 self)
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This paper presents a simple approach for rendering isosurfaces of a scalar field. Using the vertex programming capability of commodity graphics cards, we transfer the cost of computing an isosurface from the Central Processing Unit (CPU), running the main application, to the Graphics Processing Unit (GPU), rendering the images. We consider a tetrahedral decomposition of the domain and draw one quadrangle (quad) primitive per tetrahedron. A vertex program transforms the quad into the piece of isosurface within the tetrahedron (see Figure 2). In this way, the main application is only devoted to streaming the vertices of the tetrahedra from main memory to the graphics card. For adaptively refined rectilinear grids, the optimization of this streaming process leads to the definition of a new 3D space-filling curve, which generalizes the 2D Sierpinski curve used for efficient rendering of triangulated terrains. We maintain the simplicity of the scheme when constructing view-dependent adaptive refinements of the domain mesh. In particular, we guarantee the absence of T-junctions by satisfying local bounds in our nested error basis. The expensive stage of fixing cracks in the mesh is completely avoided. We discuss practical tradeoffs in the distribution of the workload between the application and the graphics hardware. With current GPU's it is convenient to perform certain computations on the main CPU. Beyond the performance considerations that will change with the new generations of GPU's this approach has the major advantage of avoiding completely the storage in memory of the isosurface vertices and triangles.
Tetrahedral projection using vertex shaders
- IEEE Symposium on Volume Visualization and Graphics
, 2002
"... Sandia National Laboratories* Projective methods for volume rendering currently represent the best approach for interactive visualization of unstructured data sets. We present a technique for tetrahedral projection using the programmable vertex shaders on current generation commodity graphics cards. ..."
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Cited by 45 (1 self)
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Sandia National Laboratories* Projective methods for volume rendering currently represent the best approach for interactive visualization of unstructured data sets. We present a technique for tetrahedral projection using the programmable vertex shaders on current generation commodity graphics cards. The technique is based on Shirley and Tuchman’s Projected Tetrahedra (PT) algorithm and allows tetrahedral elements to be volume scan converted within the graphics processing unit. Our technique requires no pre-processing of the data and no additional data structures. Our initial implementation allows interactive viewing of large unstructured datasets on a desktop personal computer.
Hardware-accelerated reconstruction of polygonal isosurface representations on unstructured grids
- In Proceedings of Pacific Graphics ’04
, 2004
"... Volume visualization using isosurface extraction is a well-researched topic. Recent research demonstrated that even for unstructured grids peak performances of millions of tetrahedra per second can be achieved by exploiting the parallel processing capabilities of modern GPUs. In this paper we presen ..."
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Cited by 36 (0 self)
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Volume visualization using isosurface extraction is a well-researched topic. Recent research demonstrated that even for unstructured grids peak performances of millions of tetrahedra per second can be achieved by exploiting the parallel processing capabilities of modern GPUs. In this paper we present a novel hardware-accelerated solution that further improves the extraction performance. In contrary to existing approaches, our technique explicitly extracts the isosurface geometry in a fragment program by rendering only a single screen-sized quadrilateral. The extracted geometry is directly written to an on-board graphics memory object allowing for direct rendering without further bus transfers. Additionally, the geometry can be manipulated by shader programs or read back to the application for further processing. Examples and application scenarios are given that can benefit from our approach. 1.
High-quality lighting and efficient pre-integration for volume rendering
- In Proceedings Joint Eurographics-IEEE TVCG Symposium on Visualization 2004 (VisSym ’04
, 2004
"... Pre-integrated volume rendering is an effective technique for generating high-quality visualizations. The precomputed lookup tables used by this method are slow to compute and can not include truly pre-integrated lighting due to space constraints. The lighting for pre-integrated rendering is therefo ..."
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Cited by 31 (3 self)
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Pre-integrated volume rendering is an effective technique for generating high-quality visualizations. The precomputed lookup tables used by this method are slow to compute and can not include truly pre-integrated lighting due to space constraints. The lighting for pre-integrated rendering is therefore subject to the same sampling artifacts as in standard volume rendering. We propose methods to speed up lookup table generation and minimize lighting artifacts. The incremental subrange integration method we describe allows interactive lookup table generation in O n 2 ¡ time without the need for approximation or hardware assistance. The interpolated preintegrated lighting algorithm eliminates discontinuities by linearly interpolating illumination along the view direction. Both methods are applicable to any pre-integrated rendering method, including cell projection, ray casting, and hardware-accelerated algorithms. 1.
The Rendering of Unstructured Grids Revisited
, 2001
"... In this paper we propose a technique for resampling scalar fields given on unstructured tetrahedral grids. This technique takes advantage of hardware accelerated polygon rendering and 2D texture mapping and thus avoids any sorting of the tetrahedral elements. Using this technique, we have built a vi ..."
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Cited by 27 (1 self)
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In this paper we propose a technique for resampling scalar fields given on unstructured tetrahedral grids. This technique takes advantage of hardware accelerated polygon rendering and 2D texture mapping and thus avoids any sorting of the tetrahedral elements. Using this technique, we have built a visualization tool that enables us to either resample the data onto arbitrarily sized Cartesian grids, or to directly render the data on a slice-by-slice basis. Since our approach does not rely on any pre-processing of the data, it can be utilized efficiently for the display of time-dependent unstructured grids where geometry as well as topology change over time.
Interactively Visualizing Procedurally Encoded Scalar Fields
- IN PROCEEDINGS OF EG/IEEE TCVG SYMPOSIUM ON VISUALIZATION VISSYM ’04 (2004), DEUSSEN O., HANSEN C., KEIM D.„ SAUPE D., (EDS
, 2004
"... While interactive visualization of rectilinear gridded volume data sets can now be accomplished using texture mapping hardware on commodity PCs, interactive rendering and exploration of large scattered or unstructured data sets is still a challenging problem. We have developed a new approach that ..."
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Cited by 25 (5 self)
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While interactive visualization of rectilinear gridded volume data sets can now be accomplished using texture mapping hardware on commodity PCs, interactive rendering and exploration of large scattered or unstructured data sets is still a challenging problem. We have developed a new approach that allows the interactive rendering and navigation of procedurally-encoded 3D scalar fields by reconstructing these fields on PC class graphics processing units. Since the radial basis functions (RBFs) we use for encoding can provide a compact representation of volumetric scalar fields, the large grid/mesh traditionally needed for rendering is no longer required and ceases to be a data transfer and computational bottleneck during rendering. Our new approach will interactively render RBF encoded data obtained from arbitrary volume data sets, including both structured volume models and unstructured scattered volume models. This procedural reconstruction of large data sets is flexible, extensible, and can take advantage of the Moore’s Law cubed increase in performance of graphics hardware.
Projecting tetrahedra without rendering artifacts
- In Proc. of IEEE Visualization (2004
"... Hardware-accelerated direct volume rendering of unstructured volumetric meshes is often based on tetrahedral cell projection, in particular, the Projected Tetrahedra (PT) algorithm and its variants. Unfortunately, even implementations of the most advanced variants of the PT algorithm are very prone ..."
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Cited by 21 (2 self)
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Hardware-accelerated direct volume rendering of unstructured volumetric meshes is often based on tetrahedral cell projection, in particular, the Projected Tetrahedra (PT) algorithm and its variants. Unfortunately, even implementations of the most advanced variants of the PT algorithm are very prone to rendering artifacts. In this work, we identify linear interpolation in screen coordinates as a cause for significant rendering artifacts and implement the correct perspective interpolation for the PT algorithm with programmable graphics hardware. We also demonstrate how to use features of modern graphics hardware to improve the accuracy of the coloring of individual tetrahedra and the compositing of the resulting colors, in particular, by employing a logarithmic scale for the pre-integrated color lookup table, using textures with high color resolution, rendering to floating-point color buffers, and alpha dithering. Combined with a correct visibility ordering, these techniques result in the first implementation of the PT algorithm without objectionable rendering artifacts. Apart from the important improvement in rendering quality, our approach also provides a test bed for different implementations of the PT algorithm that allows us to study the particular rendering artifacts introduced by these variants.
