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Item Texture Shaders(The Eurographics Association, 1999) McCool, Michael D.; Heidrich, Wolfgang; A. Kaufmann and W. Strasser and S. Molnar and B.- O. SchneiderExtensions to the texture-mapping support of the abstract graphics hardware pipeline and the OpenGL API are proposed to better support programmable shading, with a unified interface, on a variety of future graphics accelerator architectures. Our main proposals include better support for texture map coordinate generation and an abstract, programmable model for multitexturing. As motivation, we survey several interactive rendering algorithms that target important visual phenomena. With hardware implementation of programmable multitexturing support, implementations of these effects that currently take multiple passes can be rendered in one pass. The generality of our proposed extensions enable efficient implementation of a wide range of other interactive rendering algorithms. The intermediate level of abstraction of our API proposal enables high-level shader metaprogramming toolkits and relatively straightforward implementations, while hiding the details of multitexturing support that are currently fragmenting OpenGL into incompatible dialects.Item Multiresolution Rendering With Displacement Mapping(The Eurographics Association, 1999) Gumhold, Stefan; Hüttner, Tobias; A. Kaufmann and W. Strasser and S. Molnar and B.- O. SchneiderIn this paper, we present for the first time an approach for hardware accelerated displacement mapping. The displaced surface is generated from a 2D displacement map by remeshing a coarse triangle mesh according to the screen projection of the surface The remeshing algorithm is implemented in hardware. Filtered access to the displacement map makes our approach competitive with available view dependent multiresolution techniques. The advantage of displacement mapping is the compact representation. A displacement mapped surface consumes together with all filter levels only a fraction of the storage space needed for a hardware compatible representation of an equivalent triangle mesh. A possible design of the displacement mapping rendering pipeline is proposed. Previously described hardware components are used as often as possible. Our approach can be smoothly integrated into all available graphics application programming interfaces. Most existing graphics applications can be extended to the new feature with marginal effort.Item Fast Footprint MlPmapping(The Eurographics Association, 1999) Hüttner, Tobias; Straßer, Wolfgang; A. Kaufmann and W. Strasser and S. Molnar and B.- O. SchneiderMapping textures onto surfaces of computer-generated objects is a technique which greatly improves the realism of their appearance. In this paper, we describe a new method for efficient and fast texture filtering to prevent aliasing during texture mapping. This method, called Fast Footprint MIPmapping, is very flexible and can be adapted to the internal bandwrdth of a graphrcs system. It adopts the prefiltered MIPmap data structure of currently available trilinear MIPmapping implementatrons, but exploits the texels fetched from texture memory in a more optimal manner. Furthermore, like trilinear MIPmapping, fast footprint MIPmapping can easily be realized in hardware. It is sufficient to fetch only eight texels per textured pixel to achieve a significant improvement over classical trilinear MIPmapping.Item Neon: A Single-Chip 3D Workstation Graphics Accelerator(The Eurographics Association, 1998) McCormack, Joel; McNamara, Robert; Gianos, Christopher; Seiler, Larry; Jouppi, Norman P.; Correll, Ken; S. N. SpencerHigh-performance 3D graphics accelerators traditionally require multiple chips on multiple boards, including geometry, rasterizing, pixel processing, and texture mapping chips. These designs are often scalable: they can increase performance by using more chips. Scalability has obvious costs: a minimal configuration needs several chips, and some configurations must replicate texture maps. A less obvious cost is the almost irresistible temptation to replicate chips to increase performance, rather than to design individual chips for higher performance in the first place. In contrast, Neon is a single chip that performs like a multichip design. Neon accelerates OpenGL [19] 3D rendering, as well as X11 [20] and Windows/NT 2D rendering. Since our pin budget limited peak memory bandwidth, we designed Neon from the memory system upward in order to reduce bandwidth requirements. Neon has no special-purpose memories; its eight independent 32-bit memory controllers can access color buffers, 1. depth buffers, stencil buffers, and texture data. To fit our gate budget, we shared logic among different operations with similar implementation requirements, and left floating point calculations to Digital s Alpha CPUs. Neon s performance is between HP s Visualize fx<sup>4</sup> and fx<sup>6</sup>, and is well above SGI s MXE for most operations. Neon-based boards cost much less than these competitors, due to a small part count and use of commodity SDRAMs.Item High-Quality Volume Rendering Using Texture Mapping Hardware(The Eurographics Association, 1998) Dachille, Frank; Kreeger, Kevin; Chen, Baoquan; Bitter, Ingmar; Kaufman, Arie; S. N. SpencerWe present a method Jor volume rendering of regular grids which takes advantage of 3D texture mapping hardware currently, available on graphics workstations. Our method products accurate shading for arbitrary and dynamically changing directional lights, viewing parameters, and transfer functions. This is achieved by hardware interpolating the data values and gradients before software classification and shading. The method works equally well for parallel and perspective projections. We present two approaches for OUT method: one which takes advantage of software ray casting optimizations and another which takes advantage of hardware blending acceleration.Item View-independent Environment Maps(The Eurographics Association, 1998) Heidrich, Wolfgang; Seidel, Hans-Peter; S. N. SpencerEnvironment maps are widely used for approximating reflections in hardware-accelerated rendering applications. Unfortunately, the parameterizations for environment maps used in today s graphics hardware severely undersample certain directions, and can thus not be used from multiple viewing directions. Other parameterizations exist, but require operations that would be too expensive for hardware implementations. In this paper we introduce an inexpensive new parameterization for environment maps that allows us to reuse the environment map for any given viewing direction. We describe how, under certain restrictions, these maps can be used today in standard OpenGL implementations. Furthermore, we explore how OpenGL could be extended to support this kind of environment map more directly.Item Gouraud Bump Mapping(The Eurographics Association, 1998) Ernst, I.; Rüsseler, H.; Schulz, H.; Wittig, 0.; S. N. SpencerIn this paper a new low cost bump mapping hardware is prcsented. The new hardware approach does not rely on per pixel lighting, but instead uses Gouraud interpolated triangles. The bump mapping effect is applied by blending the calculated per pixel bump map color onto the fragment s color. This allows realtime animated distant light-sources to react on the specified bump map. The paper further investigates a number of different variants of recently proposed bump engines. These variants range from lowend PC solution to highest quality high-end solutions.Item Antialiased Parameterized Solid Texturing Simplified for Consumer- Level Hardware Implementation(The Eurographics Association, 1999) Hart, John C.; Carr, Nate; Karneya, Masaki; Tibbitts, Stephen A.; Coleman, Terrance J.; A. Kaufmann and W. Strasser and S. Molnar and B.- O. SchneiderProcedural solid texturing was introduced fourteen years ago, but has yet to find its way into consumer level graphics hardware for teal-time operation. To this end, a new model is introduced that yields a parameterized function capable of synthesizing the most common procedural solid textures, specifically wood, marble, clouds and fire. This model is simple enough to be implemented in hardware, and can be realized in VLSI with as little as 100,000 gates. The new model also yields a new method for antialiasing synthesized textures. An expression for the necessary box filter width is derived as a function of the texturing parameters, the texture coordinates and the rasterization variables. Given this filter width, a technique for efficiently box filtering the synthesized texture by either mip mapping the color table or using a summed area color table are presented. Examples of the antialiased results are shown.