EGGH00: SIGGRAPH/Eurographics Workshop on Graphics Hardware 2000

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https://diglib.eg.org/handle/10.2312/335

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Browsing EGGH00: SIGGRAPH/Eurographics Workshop on Graphics Hardware 2000 by Subject "Graphics Processors"

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    Adaptive View Dependent Tessellation of Displacement Maps
    (The Eurographics Association, 2000) Doggett, Michael; Hirche, Johannes; I. Buck and G. Humphreys and P. Hanrahan
    Displacement Mapping is an effective technique for encoding the high levels of detail found in today s triangle based surface models. Extending the hardware rendering pipeline to be capable of handling displacement maps as geometric primitives, will allow highly detailed models to be constructed without requiring large numbers of triangles to be passed from the CPU to the graphics pipeline. We present a new approach based on recursive tessellation that adapts to the surface complexity described by the displacement map. We also ensure that the resolution of the displaced mesh is tessellated with respect to the current view point. Our tessellation scheme performs all tests only on triangle edges to avoid generating cracks on the displaced surface. The main decision for vertex insertion is based on two comparisons involving the average height surrounding the vertices and the normals at the vertices. Individually, the tests will fail to tessellate a mesh satisfactorily, but their combination achieves good results. We propose several additions to the typical hardware rendering pipeline in order to achieve displacement map rendering in hardware. The mesh tessellation is placed within the rendering pipeline so that we can take advantage of the pre-existing vertex transformation units to perform the setup calculations for our view dependent test. Our method adds only simple arithmetic and comparison operations to the graphics pipeline and makes use of existing units for calculations wherever possible.
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    Hardware-Accelerated Free-Form Deformation
    (The Eurographics Association, 2000) Chua, Clint; Neumann, Ulrich; I. Buck and G. Humphreys and P. Hanrahan
    Hardware-acceleration for geometric deformation is developed in the framework of an extension to the OpenGL specification. The method requires an addition to the front-end of the OpenGL rendering pipeline and an appropriate OpenGL primitive. Our approach is to implement general geometric deformations so the system supports additional layers of abstraction, including physically based simulations. This approach would support a wide range of users with an accelerated implementation of a wellunderstood deformation method, reducing the need for software deformation engines and the execution time penalty associated with them.