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<body class='hmmessage'><div dir='ltr'><div>I've seen this back in that forum and tought looked great indeed. </div><div><span style="font-size: 12pt;">Is there any downside about such approach? Because from what i can see it would be great to have. </span></div><div><br></div>Many times in my scenes branched PT isn't beneficial, but with simple PT + many lights it gets impossible when dealing with tens of lamps. <div>So if standard path tracing could be optimized for many lights scenarios with this technique, i really wish someone has the ability to add it </div><div><br><div>I'd love to hear Cycles devs opinion. </div><div>Regards </div><div><br></div><div><br><div>> Date: Mon, 23 Jun 2014 16:34:16 -0700<br>> From: cessen@cessen.com<br>> To: bf-cycles@blender.org<br>> Subject: [Bf-cycles] Efficient sampling of many lights<br>> <br>> I had mentioned this to Brecht a while back, but since he won't be<br>> working on Cycles anymore I thought I'd drop a general note here.<br>> <br>> Currently Cycles either uniformly randomly chooses a single light to<br>> sample for each ray hit, or it samples all lights for each ray hit.<br>> The former significantly increases noise as you add more lights to a<br>> scene, and the latter significantly slows down rendering as you<br>> approach large numbers of lights. As far as I know, this is a problem<br>> common to all path tracers.<br>> <br>> In the process of writing my own toy renderer, I came up with a method<br>> that significantly improves on this problem and can efficiently sample<br>> among many light sources. I outline the technique in this post on<br>> ompf2, which includes some example before/after renders:<br>> http://ompf2.com/viewtopic.php?f=3&t=1938<br>> <br>> The technique is not thoroughly tested, as my renderer only supports<br>> limited light and material types. And it surely needs more design and<br>> development work. But it seems to work well, and especially for<br>> scenes with hundreds of lights or more it provides an enormous<br>> benefit.<br>> <br>> I don't currently have any plans for developing on Cycles, but I'm<br>> noting the technique here just in case anyone is interested in<br>> attempting to implement it in Cycles.<br>> <br>> --Nathan<br>> _______________________________________________<br>> Bf-cycles mailing list<br>> Bf-cycles@blender.org<br>> http://lists.blender.org/mailman/listinfo/bf-cycles<br></div></div></div> </div></body>
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