Monday, February 9, 2009

More from the new MLT algorithm

I improved it a little, and it seems to work fairly well. Now all I need is an importer, to blender or some other program, and I will open source it- well, possibly with a copyright so I can prove that I wrote it, something like PBRT has.- all except for the new MLT code, which I'd prefer to keep a secret a bit longer.

Now tell me, is this an improvment worth pursuing? Or should I go ahead and implement the paper on adaptive multi-dimensional sampling that seems to show such great improvements (does anybody know of any renderers that use this?)

Regular path tracing- 300 spp- this was the first time i tried to benchmark it without eclipse being open and me doing stuff. on my 1.9ghz core 2 duo, with 2 threads, on vista 64, i was getting an average of 10000 mps

The image after 315 spp, I'm not going to say how long this took because it was only on one core and was rendered while I was using my computer intensively.

The new algorithm after 20spp, at about 10 minutes on a dual core. -Lprob .01-.99 -maxRej 10-1000

the regular MLT algorithm with 20spp at about 10 miniutes, with an -Lprob .4 and maxrej of 500

the regular image's lprob and maxrej was set to be what the new algorithm's lprob and maxrej would average out to given thoes paremeters and scene. All MLT is based off of Keleman et al.'s robust mutation strategy paper, and paper on hybrid MLT.


  1. Very nice work. Great scene, lovely images. I am really impressed you got this to work as a university freshman! The ring image is also very nice. Very good job!

    And now a question... What do you mean by hybrid MLT?

  2. Did you mean exporter from blender? If so, then if you havent tried yet its super easy to write one :).

    how old are you? im curious whats the college age in your country.

  3. kevin- hybrid MLT= Kelemen's version of mlt where you have both large steps and small steps that means you can choose a percentage of the time you want to use MLT and a percentage of the time you want to use regular path tracing

    Neos1- 18 - Yeah, i should probably get on that and learn basic python.