Hello,
i have created an underwater scene with a volume scatter .
Problem is that after half an hour or one hour it is still full of fireflies. Many fireflies.
I don’#t intend to remove the caustic via path canceling, anyways i am searching for a method to filter the noise froma final render. Any ideas how i could achieve this?
Have you tried the “Clamp Indirect” setting in the Render Properties, under Sampling? You might want to set that to somewhere between 2 and 10. Very, very helpful for caustics.
For filtering, you can set the filter glossy value to something like 0.25 or something, that will allow the caustics to render much faster as the cost of some bias (via the softening of the effect).
I would also add to the clamp indirect idea, setting it to something above 10 will get rid of the brightest fireflies while keeping most of the pattern (though it will overall be a little dimmer).
thanks for the good advices. But clamping would mean i will take some information out. I dont want that.
I rendered the scene overnight for 4 hours, still full of white noise. 
I think i have o invest in some software.
Does anybody know which renderer is a really good caustics killer?
OCtane , Clarisse iFX?
VRay - fast, clean caustics and cheap (250€), though a bit more of technical skill is needed.
INteresting. https://www.youtube.com/watch?v=elGYl2g0D7U
How much faster is it than Blender?
Is it also good for editing?
What do you mean by editing?
VRay is a render engine, one of the best production proven industry standards, also for Blender > VRay for Blender (demo available)
It shines (fast and clean) with interiors, volumetrics, low memory consumption…
Well, editing meshes of course. Doesnt need to be a sculpting tool, but it would be nice if it can do the things Blender also does.
VRay is a render engine - and nothing else. Just as Cycles does nothing else than rendering.
The modeling/sculpting/rigging/animating etc. is done in the host application, which would be also Blender in your case (in the YouTube video you linked to it’s e. g. 3ds Max).
Could always try LuxRender with BiDir + MLT?
Thank you all for your very kind responses.
Ok, only a render engine. I should have known this since i read most of the chapters on scratch-a-pixel.com (only to recommend).
The thinsg i want to realize in my underwater scence is akin to that in Kon-tiki, if anybody knows this movie. Photoreal Sharks!!! and an Ara.
I informed myself about the Beer-Lambert - law to simulate absorption. It should be physically correct.
I found this tutorial about how to realize math functions in BLender. http://blenderdiplom.com/en/tutorials/419-tutorial-absorption-in-cycles.html
I hope that i can go without to much volume scatter.
Volume absorption with a little volume emission works fine right now.
I think i will try the demo of Clarisse iFX. It can handle volumes well and furthermore can render quadrillions of polys. ^^
I found a video in which one of the developers if told that it would be interactive at sextillion polys. Whatever this number is i didnt found it on the web… lol
I will also have a look into luxrender.
I don’t want to buy the cat in the sack if you know what i mean. XD
EDIT: The demo of Vray well was just an UI demo.