The visual inspection of a hexahedral mesh with respect to element quality is difficult due to clutter and occlusions that are produced when rendering all element faces or their edges simultaneously. Current approaches overcome this problem by using focus on specific elements that are then rendered opaque, and carving away all elements occluding their view. In this work, we make use of advanced GPU shader functionality to generate a focus+context rendering that highlights the elements in a selected region and simultaneously conveys the global mesh structure in the surrounding. To achieve this, we propose a gradual transition from edge-based focus rendering to volumetric context rendering, by combining fragment shader-based edge and face rendering with per-pixel fragment lists. A fragment shader smoothly transitions between wireframe and face-based rendering, including focus-dependent rendering style and depth-dependent edge thickness and halos, and per-pixel fragment lists are used to blend fragments in correct visibility order. To maintain the global mesh structure in the context regions, we propose a new method to construct a sheet-based level-of-detail hierarchy and smoothly blend it with volumetric information. The user guides the exploration process by moving a lens-like hotspot. Since all operations are performed on the GPU, interactive frame rates are achieved even for large meshes.

中文翻译：

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用于六面体网格检查的交互式焦点+上下文渲染

由于在同时渲染所有单元面或其边缘时会产生杂波和遮挡，因此很难对六面体网格的单元质量进行目视检查。当前的方法通过将焦点放在特定元素上，然后将这些元素渲染为不透明，并清除所有遮挡其视图的元素，从而克服了这个问题。在这项工作中，我们利用先进的 GPU 着色器功能生成焦点 + 上下文渲染，突出显示选定区域中的元素，同时传达周围的全局网格结构。为了实现这一点，我们建议通过将基于片段着色器的边缘和面部渲染与每像素片段列表相结合，从基于边缘的焦点渲染逐渐过渡到体积上下文渲染。片段着色器在线框和基于面部的渲染之间平滑过渡，包括依赖于焦点的渲染风格和依赖于深度的边缘厚度和光晕，每像素片段列表用于以正确的可见性顺序混合片段。为了在上下文区域中保持全局网格结构，我们提出了一种新方法来构建基于图纸的细节层次层次结构并将其与体积信息平滑地混合。用户通过移动类似镜头的热点来指导探索过程。由于所有操作都在 GPU 上执行，因此即使对于大型网格也能实现交互式帧速率。为了在上下文区域中保持全局网格结构，我们提出了一种新方法来构建基于图纸的细节层次层次结构并将其与体积信息平滑地混合。用户通过移动类似镜头的热点来指导探索过程。由于所有操作都在 GPU 上执行，因此即使对于大型网格也能实现交互式帧速率。为了在上下文区域中保持全局网格结构，我们提出了一种新方法来构建基于图纸的细节层次层次结构并将其与体积信息平滑地混合。用户通过移动类似镜头的热点来指导探索过程。由于所有操作都在 GPU 上执行，因此即使对于大型网格也能实现交互式帧速率。