<div dir="ltr">maybe it's the structure of the scene itself? that with 3 bounces lots of rays go crazy? it's only a sun coming through a window (interior lighting). all diffuse.</div><div class="gmail_extra"><br><div class="gmail_quote">2014-11-06 10:00 GMT-03:00 David Fenner <span dir="ltr"><<a href="mailto:d4vidfenner@gmail.com" target="_blank">d4vidfenner@gmail.com</a>></span>:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Hi Thomas, thanks for the commit yesterday, to control bounces per light, very nice!! <div><br></div><div>Been doing some tests here, and I ran into a very strange scenario:</div><div><br></div><div>When I have 3 or more max diffuse bounces in global render settings, reducing per lamp bounces have little to no impact in render times, even if set to 0 bounces. However, when I have only 2 max diffuse bounces in render settings, lowering per lamp bounces have a very big impact on render times, reducing them almost as much as if I lowered global diffuse bounces on the same quantity. It's like there was some sort of threshold at 2 global bounces. For example:</div><div><br></div><div>(on a simple diff scene with one lamp)</div><div><br></div><div><div><br></div><div>Global Max Diff Bounces = 0</div><div>Lamp bounces = 0</div><div>Render Time: 4.7 sec</div></div><div><br></div><div><br></div><div>Global Max Diff Bounces = 3</div><div>Lamp bounces = 1024</div><div>Render Time: 10 sec</div><div><br></div><div><div><br></div><div>Global Max Diff Bounces = 3</div><div>Lamp bounces = 0</div><div>Render Time: 9.7 sec (almost the same as before)</div></div><div><br></div><div><div><br></div><div>Global Max Diff Bounces = 2</div><div>Lamp bounces = 2</div><div>Render Time: 8.5 sec (lower rendertime thanks to one less bounce)</div></div><div><br></div><div><br></div><div><div>Global Max Diff Bounces = 2</div><div>Lamp bounces = 0</div><div>Render Time: 4.9 sec (before it didn't even care, yet for 2 bounces and below its almost as there where no global bounces)</div></div><div><br></div><div><br></div><div>It's great, with 2 global diff bounces and below the gains of lowering per lamp bounces are almost as big as if lowering global diffuse bounces, so having only a few lights with GI can increase your rendertimes amazingly, however, with 3 global diff bounces and over there is strangely almost no gain, even when all lamps have 0 bounces.</div><div><br></div><div><div><br></div></div><div><br></div><div> </div><div><br></div><div><br></div></div>
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