Radiance interpolants for accelerated bounded-error ray tracing
Radiance interpolants for accelerated bounded-error ray tracing
复制标题
用于加速有界误差光线追踪的辐射插值
DOI：
10.1145/336414.336417
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发表时间：
1999
期刊：
影响因子：
--
通讯作者：
S. Teller
中科院分区：
文献类型：
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作者：
Kavita Bala;Julie Dorsey;S. Teller
对辐射度进行采样的光线跟踪器通常被视为离线渲染算法，速度太慢，无法进行交互使用。在本文中，我们提出了一个利用物体空间、光线空间、图像空间和时间相干性来加速光线跟踪的系统。我们的系统使用每个表面的插值法来逼近交互式和批量光线跟踪器的辐射度。我们的方法显式解耦了光线跟踪器的两个主要操作-着色和可见性确定-并独立地加速了每一个操作。通过对延迟获取的辐射样本进行四次线性内插来加速着色。插补误差不超过用户指定的界限，允许用户控制性能/质量权衡。在不连续和辐射非线性的情况下，通过自适应采样来限制误差；在用户的视点变化时，通过重新投影内插值来加速像素上的可见性确定。然后，快速扫描线ALOGHIS在不牺牲图像质量的情况下实现高性能。对于平滑变化的视点，延迟内插和投影的组合可显著加速光线跟踪器。此外，高效的高速缓存管理算法以极小的开销保持了系统的内存占用。
Ray tracers, which sample radiance, are usually regarded as offline rendering algorithms that are too slow for interactive use. In this article we present a system that exploits object-space, ray-space, image-space, and temporal coherence to accelerate ray tracing. Our system uses per-surface interpolants to approximate radiance both interactive and batch ray tracers.Our approach explicity decouples the two primary operations of a ray tracer—shading and visibility determination—and accelerates each of them independently. Shading is accelerated by quadrilinearily interpolating lazily acquired radiance samples. Interpolation error does not exceed a user-specified bound, allowing the user to control performance/quality tradeoffs. Error is bounded by adaptive sampling at discontinuities and radiance nonlinearities.Visibility determination at pixels is accelerated by reprojecting interpolants as the user's viewpoint changes. A fast scan-line alogoithm then achieves high performance without sacrificing image quality. For a smoothly varying viewpoint, the combination of lazy interpolants and projection substantially accelerates the ray tracer. Additionally, an efficient cache management algorithm keeps the memory footprint of the system small with negilgible overhead.