Selectively metropolised Monte Carlo light transport simulation
Selectively metropolised Monte Carlo light transport simulation
复制标题
选择性都市蒙特卡罗光传输模拟
DOI：
10.1145/3355089.3356578
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发表时间：
2019
影响因子：
6.2
通讯作者：
Jarosz, Wojciech
中科院分区：
文献类型：
--
作者：
Bitterli, Benedikt;Jarosz, Wojciech
光传输是一个复杂的问题，有许多解决方案。从业者现在面临着为任何给定场景选择使用哪种渲染算法的艰巨任务。简单的蒙特卡罗方法(如路径跟踪)适用于大多数照明场景，但在遇到无法采样的传输(如焦散)时会产生过大的变化。更复杂的渲染算法，如双向路径跟踪，可以稳健地处理更大类别的灯光传输，但具有较高的计算开销，这使得它们对于不是以困难的传输为主的场景效率低下。潜在的问题是，渲染算法只能在所有传输上不加区别地执行，即使它们可能只对路径的子集提供改进。在本文中，我们介绍了一种新的方案，有选择地结合不同的蒙特卡罗渲染算法。我们使用简单的传输方法(例如路径跟踪)作为基础，并将高方差的“萤火虫”视为马尔可夫链的种子，该马尔可夫链在本地使用更复杂的传输方法的大都会版本进行探索，以公正的方式移除萤火虫。我们使用了一种受多重重要性采样启发的加权方案，将被积函数划分为基本方法可以很好采样的区域和不能采样的区域，而对于后者只使用Metropolis。这将马尔科夫链限制在提供改进的路径上，并使其远离已经由基本估计器很好地处理的区域。结合分层初始化、短链长度和仔细的样本分配，这极大地减少了Metropolis方法在全球应用时通常遇到的非均匀噪声和时间闪烁伪影。通过仔细的设计选择，我们确保我们的算法永远不会比基本估计器的性能差得多，而且通常性能要好得多，从而减少了为每个场景试验不同算法的需要。
Light transport is a complex problem with many solutions. Practitioners are now faced with the difficult task of choosing which rendering algorithm to use for any given scene. Simple Monte Carlo methods, such as path tracing, work well for the majority of lighting scenarios, but introduce excessive variance when they encounter transport they cannot sample (such as caustics). More sophisticated rendering algorithms, such as bidirectional path tracing, handle a larger class of light transport robustly, but have a high computational overhead that makes them inefficient for scenes that are not dominated by difficult transport. The underlying problem is that rendering algorithms can only be executed indiscriminately on all transport, even though they may only offer improvement for a subset of paths. In this paper, we introduce a new scheme for selectively combining different Monte Carlo rendering algorithms. We use a simple transport method (e.g. path tracing) as the base, and treat high variance "fireflies" as seeds for a Markov chain that locally uses a Metropolised version of a more sophisticated transport method for exploration, removing the firefly in an unbiased manner. We use a weighting scheme inspired by multiple importance sampling to partition the integrand into regions the base method can sample well and those it cannot, and only use Metropolis for the latter. This constrains the Markov chain to paths where it offers improvement, and keeps it away from regions already handled well by the base estimator. Combined with stratified initialization, short chain lengths and careful allocation of samples, this vastly reduces non-uniform noise and temporal flickering artifacts normally encountered with a global application of Metropolis methods. Through careful design choices, we ensure our algorithm never performs much worse than the base estimator alone, and usually performs significantly better, thereby reducing the need to experiment with different algorithms for each scene.
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DOI：
10.1145/15922.15901
发表时间：
1986-08
期刊：
Proceedings of the 13th annual conference on Computer graphics and interactive techniques
影响因子：
--
作者：
David S. Immel;Michael F. Cohen;D. Greenberg
通讯作者：
David S. Immel;Michael F. Cohen;D. Greenberg
DOI：
10.1145/2601097.2601203
发表时间：
2014-07
期刊：
ACM Transactions on Graphics (TOG)
影响因子：
--
作者：
J. Vorba;Ondrej Karlik;M. Šik;Tobias Ritschel;Jaroslav Křivánek
通讯作者：
J. Vorba;Ondrej Karlik;M. Šik;Tobias Ritschel;Jaroslav Křivánek
DOI：
10.1145/2641762
发表时间：
2014-09
期刊：
ACM Transactions on Graphics (TOG)
影响因子：
--
作者：
Bochang Moon;N. Carr;Sung-eui Yoon
通讯作者：
Bochang Moon;N. Carr;Sung-eui Yoon
使用半球形粒子足迹进行重要采样
DOI：
--
发表时间：
2002
期刊：
Spring conference on Computer graphics
影响因子：
--
作者：
H. Hey;W. Purgathofer
通讯作者：
W. Purgathofer
制作中的路径追踪 - 第 2 部分：制作电影
DOI：
--
发表时间：
2017
期刊：
SIGGRAPH Courses
影响因子：
--
作者：
Luca Fascione;J. Hanika;Rob Pieké;Christophe Hery;Ryusuke Villemin;Thorsten;Christopher D. Kulla;D. Heckenberg;A. Mazzone
通讯作者：
A. Mazzone