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<body class='hmmessage'><div dir='ltr'><div>Ah well i thought this one was a lot better than other similar or offline methods.</div><div>Regarding such approximations (irradiance caching) i tried to involve a couple of guys in the past months but without success yet.</div><div><br></div><div>Approximations aside, the upcoming Siggraph seems will have a nice focus on</div><div>more advanced light transport, focusing on usability from the VFX and Architecture side too, </div><div>and indeed such <span style="font-size: 12pt;">approximation seems are going to disappear in some way,</span></div><div><span style="font-size: 12pt;">or at least progressively abandoned...according to </span><a href="http://cgg.mff.cuni.cz/~jaroslav/papers/2014-ltstutorial/index.htm" style="font-size: 12pt;">these slides</a><span style="font-size: 12pt;"> path tracing is the most used</span></div><div>but it seems industry proven renderers are considering/investigating more recent and advanced methods too. (see next link) **</div><div>In part it's a matter of "breaking" artists workflows again, and the good visual feedback unidirectional PT provides.</div><div><br></div><div>Perhaps simple path tracing will be replaced by some BiDir derivate, how you see this trend?</div><div>There will be a course held by Pixar, Fajardo, the Corona render guy, Nvidia, Next Limit...</div><div>** <a href="http://www.iliyan.com/publications/Siggraph2014Course">http://www.iliyan.com/publications/Siggraph2014Course</a></div><div>** <a href="http://www.iliyan.com/publications/Siggraph2014Course/Siggraph2014Course_Syllabus.pdf">Syllabus</a><br></div><div><br></div><div>One of the guy behind Vertex Connection and Merging is currently working at Solid Angle,</div><div>and VCM is going to hit Renderman 19 too (and already integrated in Vray and Corona, see link, last sildes)</div><div><a href="http://cgg.mff.cuni.cz/~jaroslav/papers/2014-ltstutorial/04%20-%20ltstutorial%20-%20ppm+bpt%20-%20georgiev%20-%20notes.pdf">http://cgg.mff.cuni.cz/~jaroslav/papers/2014-ltstutorial/04%20-%20ltstutorial%20-%20ppm+bpt%20-%20georgiev%20-%20notes.pdf</a><br></div><div><br></div><div>By the way, a first implementation of VCM on GPU has appeared, </div><div>and this link in particular also focus on making difficult light transport algorithms more efficient on GPUs.</div><div><a href="http://cgg.mff.cuni.cz/~jaroslav/papers/2014-gpult/index.htm">http://cgg.mff.cuni.cz/~jaroslav/papers/2014-gpult/index.htm</a><br></div><div><br></div><div>Lastly, found this one which improve BiDir dramatically according to the examples, but still unreleased.</div><div><a href="http://cgg.mff.cuni.cz/~jaroslav/papers/2014-onlineis/index.htm">http://cgg.mff.cuni.cz/~jaroslav/papers/2014-onlineis/index.htm</a><br></div><div><br></div><div>So to conclude, BiDir or some of its evolution will be the next state-of-the-art approach?</div><div>How feasible will be for Cycles to switch to BiDir in the future, if it will be proven to be the best choice? (given enough man-power)</div><div><br></div><div>Regards, </div><div>MG</div><br><div>> From: brechtvanlommel@pandora.be<br>> Date: Wed, 7 May 2014 00:03:28 +0200<br>> To: bf-cycles@blender.org<br>> Subject: Re: [Bf-cycles] Interactive GI filtering paper<br>> <br>> There's a lot of such filtering papers and it's closely related to<br>> irradiance caching. Certainly such methods would be useful for faster<br>> previews and rendering still images. There's simple algorithms and<br>> complex ones with different tradeoffs and inaccuracies. If people want<br>> to contribute code for this kind of thing that can fit fine.<br>> <br>> For animations however any method that does such filtering is tricky<br>> to get working without flickering / low frequency noise. The new<br>> papers in this area do not actually improve accuracy / reliability<br>> over irradiance caching as far as I can tell, they're worse but more<br>> general or quicker. Irradiance caching with all the tricks that have<br>> been developed for it over the years might still be the least flickery<br>> of all for the problem of diffuse indirect light.<br>> <br>> I don't know of other reliable algorithms for animation that also<br>> provide a big speedup for the simple cases. Mostly it seems that<br>> Cycles could handle the difficult geometry, shader lighting cases<br>> better with various changes, but if you want a big speedup for the<br>> simpler cases then some sort of filtering or caching method with the<br>> associated tradeoffs is the only solution I know of.<br>> <br>> Brecht.<br>> <br>> <br>> <br>> <br>> On Tue, May 6, 2014 at 10:35 PM, Marco G <digitalbath86@hotmail.com> wrote:<br>> > Hi all,<br>> > just stumbled upon this paper, i'd be curious to know what Cycles devs think<br>> > about such technique,<br>> > results seems quite accurate and unlike other filtering/reconstruction<br>> > methods, it is done online interactively.<br>> ><br>> > link - http://graphics.berkeley.edu/papers/Udaymehta-IPB-2013-07/index.html<br>> ><br>> > Would something like this be unusable, introducing a lot of inaccuracy? (or<br>> > complexity to the code..?)<br>> > Speaking more in general, isn't there any idea (for the future) to<br>> > help/simplify diffuse-indirect calculation? (not Irradiance cache related,<br>> > but something animation-friendly)<br>> ><br>> > Thanks,<br>> > regards.<br>> ><br>> > _______________________________________________<br>> > Bf-cycles mailing list<br>> > Bf-cycles@blender.org<br>> > http://lists.blender.org/mailman/listinfo/bf-cycles<br>> ><br>> _______________________________________________<br>> Bf-cycles mailing list<br>> Bf-cycles@blender.org<br>> http://lists.blender.org/mailman/listinfo/bf-cycles<br></div>                                            </div></body>
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