Title: apophysis7x15D render issue - single vs. multithreading - help?! Post by: Haven on May 05, 2013, 01:01:12 PM ok...so this is the 3rd time recently i came across this issue in last couple of weeks. i noticed that some of my fractals look different from the preview after i render them...and i mean different in not a good way, sometimes the image just dissappears or is blurred, depending on the case. so i did some experimenting and it turned out the issue is in multithreading. When rendered with multithreading option enabled, the image (in those 3 cases as far as i can tell so far) went to crap...however, when rendered only using a single core option only, the image turned out to look exacty the same as the preview image. anybody any ideas or explanations? it is rather irritating having to render using only one core :/
btw...i am using two computers to render images, same issue on both of them. thx a lot for any info. update: i ran couple more tests and found out that the only common denominator is blur variation...every time i had a blur variation in one of the triagles the image turned out blurry when rendered using multithreading, but normal when using only one core. this issue was not presented in other renders that did not have blur variation in it. could anybody try and confirm this please? i tried this on two different computers, both running apo7x15D64bit version. thx a lot! Title: Re: apophysis7x15D render issue - single vs. multithreading - help?! Post by: Dinkydau on May 05, 2013, 03:50:47 PM I can confirm. I have no idea why this happens, but before you make any final render, test if it renders correctly if you want to use multithreading.
I can also advice you that the efficiency of multithreading in apophysis is often really bad. You're probably better off rendering multiple images at the same time, but I understand that may not always be an option. If you have an intel CPU with hyperthreading, disable hyperthreading (HT technology) in the bios because it makes multithreading in apophysis much better. Some variations do multithread well, though. I know the mandelbrot variation for apophysis is one of them. Title: Re: apophysis7x15D render issue - single vs. multithreading - help?! Post by: lycium on May 05, 2013, 07:04:12 PM I still need to finish writing up a page for the Chaotica website with render comparisons, showing how basically all versions of Apophysis are broken with multithreading... Apo 7x15D is probably the worst offender, with 2.09 single threaded producing the only correct solution. It doesn't have anything to do with HyperThreading, it's Apo being broken in a bunch of different (interacting) ways. These issues have been reported, but there isn't really anyone working on Apophysis since quite some time... |