Free adaptive tessellation strategy of bézier surfaces

[Abstract] Rendering of Bézier surfaces is currently performed by tessellating the model on the GPU and rendering the highly detailed triangle mesh. Whereas non-adaptive strategies apply the same tessellation pattern to the whole surface resulting in a uniform tessellation of the patch, adaptive approaches make it possible to reduce the number of triangles generated without a loss of quality. However, the most usual approaches to adaptive tessellation have little flexibility and do redundant computations and memory accesses, as each sample is independently evaluated in the Domain Shader of the DirectX11 pipeline. In this paper an adaptive tessellation technique based on the exploitation of the spatial coherence data within each surface is presented. The GPU implementation of this technique is simple and efficient and, as consequence, the tessellation of complex models can be performed in real-time. The analysis of the GPU performance and limitations for different adaptive degree of the tessellation performed suggest innovations in future graphics card generations for supporting a larger degree of adaptivity without a penalty

Parallel Hierarchical Radiosity on Hybrid Platforms

The final publication is available at Springer via http://dx.doi.org/10.1007/s11227-011-0592-6[Abstract] Achieving an efficient realistic illumination is an important aim of research in computer graphics. In this paper a new parallel global illumination method for hybrid systems based on the hierarchical radiosity method is presented. Our solution allows the exploitation of systems that combine independent nodes with multiple cores per node. Thus, multiple nodes work in parallel in the computation of the global illumination for the same scene. Within each node, all the available computational cores are used through a shared-memory multithreading approach. The good results obtained in terms of speedup on several distributed-memory and shared-memory configurations show the versatility of our hybrid proposal.[Resumo] Acadar unha eficiente iluminación realista é un importante obxectivo no campo dos gráficos por computadora. Neste traballo preséntase un novo método de iluminación global paralelo para sistemas híbridos baseado no modelo de radiosidade jerárquica. A nosa solución permite a explotación de sistemas que combinen nodos de cómputo independentes con múltiples núcleos de execución en cada nodo. Deste xeito, varios nodos traballan en paralelo na computación da iluminación global dunha mesma escea. Dentro de cada nodo, todos os núcleos computacionais dispoñibles son aproveitados mediante unha aproximación multifío en memoria compartida. Os bos resultados obtidos en canto a aceleración en distintas configuracións de memoria compartida e distribuída dan mostra da versatilidade da nosa proposta híbrida.Xunta de Galicia; INCITE08PXIB105161PRMinisterio de Educación y Ciencia; MEC TIN 2010-16735Xunta de Galicia; 08TIC001206P

Synthesis of Multiresolution Scenes with Global Illumination on a GPU

[Abstract] The radiosity computation has the important feature of producing view independent results, but these results are mesh dependent and, in consequence, are attached to a specific level of detail in the input mesh. Therefore, rendering at iterative frame rates would benefit from the utilization of multiresolution models. In this paper we focus on the rendering stage of a solution for hierarchical radiosity for multiresolution systems. This method is based on the application of an enriched hierarchical radiosity algorithm to an input scene with low resolution objects (represented by coarse meshes), and the efficient data management of the resulting values. The proposed encoding makes it possible to apply the color values obtained for the coarse objects to detailed versions of these objects during the rendering phase. These finer meshes are obtained by a standard mesh subdivision strategy, such as the Loop subdivision scheme. Our solution performs the whole rendering stage of this multiresolution approach on the GPU, implementing it in the geometry shader using Microsoft HLSL. Results of our implementation show an important reduction in computational costs